We publish our financial statements in New Taiwan dollars, the lawful currency of the R.O.C. In this annual report, “$”, “US$” and “U.S. dollars” mean United States dollars, the lawful currency of the United States, and “NT$” and “NT dollars” mean New Taiwan dollars. This annual report contains translations of certain NT dollar amounts into U.S. dollars at specified rates solely for the convenience of the reader. The translations from NT dollars to U.S. dollars and from U.S. dollars to NT dollars for periods through December 31, 2008 were made at the year-end noon buying rate in The City of New York for cable transfers in NT dollars per U.S. dollar as certified for customs purposes by the Federal Reserve Bank of New York. For January 1, 2009 and all later dates and periods, the exchange rate refers to the exchange rate as set forth in the statistical release of the Federal Reserve Board. Unless otherwise noted, all translations for the year 20102012 were made at the exchange rate as of December 30, 2010,31, 2012, which was NT$29.1429.05 to US$1.00. On April 8, 2011,March 29, 2013, the exchange rate was NT$28.9229.81 to US$1.00.

The following table sets forth, for the periods indicated, information concerning the number of NT dollars for which one U.S. dollar could be exchanged.

No representation is made that the NT dollar or U.S. dollar amounts referred to herein could have been or could be converted into U.S. dollars or NT dollars, as the case may be, at any particular rate or at all.

Not applicable.

Not applicable.

We wish to caution readers that the following important factors, and those important factors described in other reports submitted to, or filed with, the Securities and Exchange Commission, among other factors, could affect our actual results and could cause our actual results to differ materially from those expressed in any forward-looking statements made by us or on our behalf, and that such factors may adversely affect our business and financial status and therefore the value of your investment:

Any global systemic political, economic and financial crisis or catastrophe caused or induced bycatastrophic natural disasters (as well as the indirect effects flowing therefrom) could negatively affect our business, results of operations, and financial condition.

In recent times, several major systemic economic and financial crisis that hadcrises and natural disasters negatively affected global business, banking and financial sectors, had also affectedincluding the semiconductor market. The 2008industry and markets. These types of crises cause turmoil in global markets resultedthat often result in sharp declines in electronic products sales from which we generate our income through our goods and services. There wereIn addition, these crises may cause a number of indirect effects such as undermining the ability of our customers to remain competitive vis-à-vis the financial and economic challenges created by insolvent countries and companies still struggling to survive in the wake of these crises. For example, there could be in the future a number of knock-on effects from such turmoilthese types of crises on our business, including significant decreases in orders from our customers; insolvency of key suppliers resulting in product delays; inability of customers to obtain credit to finance purchases of our products and/orproducts; customer insolvencies; and counterparty failures negatively impacting our treasury operations. For example, ongoing social unrest in certain oil producing countries could constrain the supply of oil that could have an adverse effect on the global economy and decline in demand for electronic products. The effects of the recent earthquake which hit Japan may disrupt global demand for electronic products and services. Any future systemic political, economic or financial crisis or catastrophic natural disasters induced catastrophedisaster (as well as the indirect effects flowing from these crises or disasters) could cause revenues for the semiconductor industry as a whole to decline dramatically, which industry is subject to unexpected change in response to fluctuating global market conditions. Also,and if the economic conditions or the financial condition of our customers were to deteriorate, additional accounting related allowances may be required in the future and such additional allowances wouldcould increase our operating expenses and therefore reduce our operating income and net income. AnyThus, any future global economic crisis or catastrophes induced bycatastrophic natural disastersdisaster (and their indirect effects) could materially and adversely affect our results of operations.

The electronics industries and semiconductor market and microelectronics industries have historically been cyclical and subject to significant and often rapid increases and decreases in product demand. Our semiconductor foundry business is affected by market conditions in such highly cyclical semiconductorelectronics and microelectronicssemiconductor industries. Most of our customers operate in these industries. Variations in order levels from our customers result in volatility in our revenues and earnings. From time to time, the semiconductorelectronics and microelectronicssemiconductor industries have experienced significant and sometimes prolonged periods of downturns and overcapacity. Any systemic economic, political, or financial crisis, such as the one that occurred in 2008-2009, could create significant volatility and uncertainty within the semiconductorelectronics and microelectronicssemiconductor industries which may disrupt traditional notions of cyclicality within such industries. As such, the nature, extent and scope of such periods of downturns and overcapacity may vary drastically in accordance with the degree of volatility of market demand. Because we are, and will continue to be, dependent on the requirements of semiconductorelectronics and microelectronicssemiconductor companies for our services, periods of downturns and overcapacity in the general semiconductorelectronics and microelectronicssemiconductor industries lead to reduced demand for overall semiconductor foundry services, including our services. If we cannot take appropriate actions such as reducing our costs to sufficiently offset declines in demand, our revenues, margin and earnings will suffer during periods of downturns and overcapacity.

A vast majority of our sales revenue is derived from customers who use our services in communication devices, personal computers, and consumer electronics products and industrial/standard products. Any decrease in the demand for theany one of these products may decrease the demand for such other products as well as overall global semiconductor foundry services, including our services and may adversely affect our revenues. Further, because we own most of our manufacturing capacities, a significant portion of our operating costs are fixed because we own most of our manufacturing capacities.is fixed. In general, these costs do not decline when customer demand or our capacity utilization rates drop, and thus declines in customer demand, among other factors, may significantly decrease our margins. Conversely, as product demand rises and factory utilization increases, the fixed costs are spread over increased output, which can improve our margins. In addition, the historical and current trend of declining average selling prices (or “ASP”) of end use applications places downward pressure on the prices of the components that go into such applications. If the ASP of end use applications continues decreasing, the pricing pressure on components produced by us may lead to a reduction of our revenues, margin and earnings.

The semiconductor industry and its technologies are constantly changing. We compete by developing process technologies using increasingly advanced nodes and on manufacturing products with more functions. We also compete by developing new derivative technologies. If we do not anticipate these changes in technologies and rapidly develop new and innovative technologies, or our competitors unforeseeably gain sudden access to additional technologies, we may not be able to provide foundry services on competitive terms. In addition, our customers have significantly decreased the time in which their products or services are launched into the market. If we are unable to meet these shorter product time-to-market, we risk losing these customers. These challenges also place greater demands on our research and development capabilities. If we are unable to innovate new technologies that meet the demands of our customers, our revenues may decline significantly. Although we have concentrated on maintaining a competitive edge in research and development, if we fail to achieve advances in technologies or processes, or to obtain access to advanced technologies or processes developed by others, we may become less competitive.

We perform periodicregular long term market demand forecasts to estimate market and general economic conditions for our products and services. Based upon these estimates, we manage our overall capacity which may increase or decrease in accordance with market demand. Because market conditions may vary significantly and unexpectedly, our market demand forecast may change significantly at any time. Further, since certain manufacturing lines or tools in some of our manufacturing facilities may be placed in “warm mode”suspended or suspendedshut down temporarily during periods of decreased demand, we may not be able to ramp up in a timely manner during periods of increased demand. During periods of continued decline in demand, our operating facilities may not be able to absorb and complete in a timely manner outstanding orders re-directed from shuttered facilities. Based on demand forecasts, we have been adding capacity to our 300mm wafer fabs in the Hsinchu Science Park, and TainanSouthern Taiwan Science Park respectively.and Central Taiwan Science Park. Total monthly capacity for 300mm wafer fabs was increased from 154,300 wafers as of December 31, 2008 to 171,400 wafers as of December 31, 2009 and to 244,600 wafers as of December 31, 2010.2010 to 290,100 wafers as of December 31, 2011 and to 366,800 wafers as of December 31, 2012. Expansion and modification of our production facilities will, among other factors, increase our costs. For example, we will need to purchase additional equipment, train personnel to operate the new equipment or hire additional personnel. If we do not increase our net sales accordingly, in order to offset these higher costs, our financial performance may be adversely affected. See “Item 4. Information on the Company — Capacity Management and Technology Upgrade Plans” for a further discussion.

Capital requirements are difficult to plan in the highly dynamic, cyclical and rapidly changing semiconductor industry. From time to time and increasingly so for the foreseeable next few years, we will continue to need significant capital to fund our operations and manage our capacity in accordance with market demand. Our continued ability to obtain sufficient external financing is subject to a variety of uncertainties, including:

Sufficient external financing may not be available to us on a timely basis, on reasonable market terms, or at all. As a result, we may be forced to curtail our expansion and modification plans or delay the deployment of new or expanded services until we obtain such financing.

We depend on the continued services and contributions of our executive officers and skilled technical and other personnel. Our business could suffer if we lose, for whatever reasons, the services and contributions of some of these personnel and we cannot adequately replace them, or if we suffer disruptions to our production operations arising from labor or industrial disputes.them. We may be required to increase or reduce the number of employees in connection with any business expansion or contraction, in accordance with market demand for our products and services. Since there is intense competition for the recruitment of these personnel, we cannot ensure that we will be able to fulfill our personnel requirements or rehire such reduced personnel on comparable terms in a timely manner during an economic upturn.

Our operations and ongoing expansion plans depend on our ability to obtain an appropriate amount of equipment and related services from a limited number of suppliers in a market that is characterized from time to time by limited supply and long delivery cycles. During such times, supplier-specific or industry-wide lead times for delivery can be as long as six months or more. Also, the effects of the recent earthquake which hit Japan may make such supply even more limited and may further lengthen delivery cycles. To better manage our supply chain, we have implemented various business models and risk management contingencies with suppliers to shorten the procurement lead time. We also provide our projected demand for various items to many of our equipment suppliers to help them plan their production in advance. We have purchased used tools and continue to seek opportunities in acquiringto acquire relevant used tools. Further, the growing complexities especially in next-generation lithographic technologies may delay the timely availability of the equipments and parts needed to exploit time sensitive business opportunities and also increase the market price for such equipment and parts. If we are unable to obtain equipment in a timely manner to fulfill our customers’ orders, or at a reasonable cost, our financial condition and results of operations could be negatively impacted.

Our production operations require that we obtain adequate supplies of raw materials, such as silicon wafers, gases, chemicals, and photoresist, on a timely basis. ShortagesIn the past, shortages in the supply of some materials, experiencedwhether by specific vendors or by the semiconductor industry generally, have in the past resulted in occasional industry-wide price adjustments and delivery delays. Also, since we procure some of our raw materials from sole-source suppliers, there is a risk that our need for such raw materials may not be met when needed or that back-up supplies may not be readily obtainable. Many of our raw materials are sourced from Japan. The effects of the recent earthquake that hit Japan may undercut our ability to procure on a timely basis sufficient raw materials to produce our products and render our services.available. Our revenue and earnings could decline if we are unable to obtain adequate supplies of the necessary raw materials in a timely manner or if there are significant increases in the costs of raw materials that we cannot pass on to our customers.

According to our agreement with the Industrial Technology Research Institute of Taiwan, or ITRI, the Ministry of Economic Affairs of the R.O.C., or an entity designated by the Ministry of Economic Affairs, has an option to purchase up to 35% of certain of our capacity, if our outstanding commitments to our customers are not prejudiced. Although the Ministry of Economic Affairs has never exercised this option, if this option is exercised to any significant degree during tight market conditions, we may not be able to provide services to all of our other customers unless we are able to increase our capacity accordingly or outsource such increased demand and in a timely manner.

Our ability to compete successfully and to achieve future growth will depend in part on the continued strength of our intellectual property portfolio. While we actively enforce and protect our intellectual property rights, there can be no assurance that our efforts will be adequate to prevent the misappropriation or improper use of our proprietary technologies, trade secrets, software or know-how. Also, we cannot assure you that, as our business or business models expand into new areas, or otherwise, we will be able to develop independently the technologies, trade secrets, patents, software or know-how necessary to conduct our business or that we can do so without unknowingly infringing the intellectual property rights of others. As a result, we may have to rely increasingly on licensed technologies and patent licenses from others. To the extent that we rely on licenses from others, there can be no assurance that we will be able to obtain any or all of the necessary licenses in the future on terms we consider reasonable or at all. The lack of necessary licenses could expose us to claims for damages and/or injunctions from third parties, as well as claims for indemnification by our customers in instances where we have contractually agreed to indemnify our customers against damages resulting from infringement claims.

We and many of our suppliers use highly combustible and toxic materials in our manufacturing processes and are therefore subject to the risk of loss arising from explosion, fire, or environmental influences which cannot be completely eliminated. Although we maintain many overlapping risk prevention and protection systems, as well as comprehensive fire and casualty insurance, including insurance for loss of property and loss of profit resulting from business interruption, our risk management and insurance coverage may not be sufficient to cover all of our potential losses. If any of our fabs or vendor facilities were to be damaged, or cease operations as a result of an explosion, fire, or environmental influences, it could reduce our manufacturing capacity and may cause us to lose important customers, thereby having a potentially adverse and material impact on our financial performance.

Under R.O.C. GAAP and U.S. GAAP, we are required to evaluate our investments, long-lived assets and intangible assets for impairment whenever triggering events or changes in circumstances indicate that the asset may be impaired and carrying value may not be recoverable.impaired. If certain criteria are met, we are required to record an impairment charge. We are also required under R.O.C. GAAP and U.S. GAAP to evaluate goodwill for impairment at least on an annual basis or more frequently whenever triggering events or changes in circumstances indicate that goodwill may be impaired and the carrying value may not be recoverable.

We currently are not able to estimate the extent or timing of any impairment charge for future years. Any impairment charge required may have a material adverse effect on our net income.

The determination of an impairment charge at any given time is based significantly on our expected results of operations over a number of years subsequent to that time. As a result, an impairment charge is more likely to occur during a period when our operating results are otherwise already depressed. See “Item 5. Operating and Financial Review and Prospects — Critical Accounting Policies” for a discussion of how we assess if an impairment charge is required and, if so, how the amount is determined.

Over the years, our customer profile and the nature of our customers’ business have changed dramatically. While we generate revenue from hundreds of customers worldwide, our ten largest customers accounted for approximately 53%54%, 53%56% and 54%59% of our net sales in 2008, 20092010, 2011 and 2010,2012, respectively. Our largest customer accounted for 14%9%, 10%14% and 9%17% of our net sales in 2008, 20092010, 2011 and 2010,2012, respectively. This customer concentration results in part from the changing dynamics of the electronics industry with the structural shift to mobile devices and applications and software that provide the content for such devices. There are only a limited number of customers who are successfully exploiting this new business model paradigm. Also, in order to respond to the new business model paradigm, we have seen the nature of our customers’ business model changes. For example, there is a growing trend toward the rise of system houses that operate in a manner which make their products and services more marketable in a changing consumer market. The loss of, or significant curtailment of purchases by, one or more of our top customers, including curtailments due to increased competitive pressures, industrial consolidation, a change in the design,their designs, or change in their manufacturing sourcing policies or practices of these customers, or the timing of customer or distributor inventory adjustments, or change in our major customers’ business models may adversely affect our results of operations and financial condition.

Effective internal controls are necessary for us to provide reasonable assurance with respect to our financial reports and to effectively prevent fraud. If we cannot provide reasonable assurance with respect to our financial reports and effectively prevent fraud and corruption, our reputation and results of operations could be harmed.

We are required to comply with various R.O.C. and U.S. laws and regulations on internal controls. For example, pursuant to Section 404 of the Sarbanes-Oxley Act of 2002, beginning with the Annual Report on Form 20-F for the fiscal year ended December 31, 2006, we are required to furnish a report by management on our internal control over financial reporting, including management’s assessment of the effectiveness of our internal control over financial reporting. Moreover, R.O.C. law requires us to establish internal control systems that would reasonably ensure the effectiveness and efficiency of operations, reliability of financial reporting, and compliance with applicable laws and regulations. We are also required under R.O.C. law to file an internal control declaration within four months of the end of each fiscal year.

Internal controls may not prevent or detect misstatements because of their inherent limitations, including the possibility of human error, the circumvention or overriding of controls, fraud or corruption. Therefore, even effective internal controls can provide only reasonable assurance with respect to the preparation and fair presentation of financial statements. In addition, projections of any evaluation of effectiveness of internal controls to future periods are subject to the risk that the internal controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate. If we fail to maintain the adequacy of our internal controls, including any failure to implement required new or improved controls, or if we experience difficulties in their implementation, our business and operating results could be harmed, we could fail to meet our reporting obligations, and there could be a material adverse effect on the market price of our common shares and ADSs.

Our principal executive officers and our principal production facilities are located in the R.O.C., and a substantial majority of our net revenues are derived from our operations in the R.O.C. In addition, we have operations worldwide and a significant percentage of our revenue comes from sales to locations outside the R.O.C. Operating in the R.O.C. and overseas exposes us to changes in policies and laws, as well as the general political and economic conditions, security risks, health conditions and possible disruptions in transportation networks, in the various countries in which we operate, which could result in an adverse effect on our business operations in such countries and our results of operations as well as the market price and the liquidity of our ADSs and common shares.

For example, even though the R.O.C. and the PRC have co-existed for the past 6163 years and significant economic and cultural relations have been established during that time, the financial markets have viewed certain past developments in relations between the two sides as occasions to depress general market prices of the securities of Taiwanese companies, including our own. In addition, the R.O.C. government has not lifted some trade and investment restrictions imposed on Taiwanese companies on the amount and types of certain investments that can be made in Mainland China.

The apparent frequency and severity of natural disasters has increased recently due to environmental and climate-related changes.recently. We have manufacturing and other operations in locations subject to natural disasters, such as severe weather, tsunamisflooding, earthquakes and other flooding, and earthquakes,tsunamis, as well as interruptions or shortages in the supply of utilities, such as water and electricity, which could disrupt operations. We have operations in earthquake-prone locations and any major natural disaster occurring in any such locations may cause severe disruptions to our business operations and financial performance. In addition, our suppliers and customers also have operations in such locations. For example, most of our production facilities, as well as those of many of our suppliers and customers and upstream providers of complementary semiconductor manufacturing services, are located in Taiwan and Japan, which are susceptible to earthquakes, tsunamis, flooding, typhoons, and droughts from time to time. In addition, we have sometimes suffered power outages in Taiwan caused throughby difficulties encountered by our electricity supplier, the Taiwan Power Company, or other power consumers on the same power grid, which have resulted in interruptions to our production schedule. No guarantee can be given, however,While our business continuity management and emergency response plans are intended to prevent or minimize losses in the future, there is no assurance that the measures will fully eliminate the losses or the insurance will fully cover any losses and our emergency response plans will be effective in preventing or minimizing losses in the future.losses. One or more natural disasters or interruptions to the supply of utilities that results in a prolonged disruption to our operations, or the operations of our customers or suppliers, may adversely affect the resultresults of our operations and financial conditions.

The manufacturing, assembling and testing of our products require the use of chemicals and materials that are subject to environmental, climate-related, and health and safety laws and regulations issued worldwide. Although we may be eligible for various exemptions and/or extensions of time for compliance, our failure to comply with any of these applicable laws or regulations could result in:

Existing and future environmental and climate related laws and regulations as well as applicable international accords to which we are subject, could also require us, among other things, to do the following: (a) purchase, use or install expensive pollution control, reduction or remediation equipment; (b) implement climate change mitigation programs and “abatement or reduction of greenhouse gas emissions” programs, or “carbon credit trading” programs; (c) modify our product designs and manufacturing processes, or incur other significant expenses associated with such laws and regulations such as obtaining substitute raw materials or chemicals that may cost more or be less available for our operations. It is still unclear whether such necessary actions would affect the reliability or efficiency of our products and services.

Any of the above contingencies resulting from the actual and potential impact of local or international laws and regulations, as well as international accords on environmental or climate change, could harm our business and operational results by increasing our expenses or requiring us to alter our manufacturing and assembly and test processes. For further details, please see our compliance record with Taiwan and international environmental and climate related laws and regulations in “Item 4. Information on the Company — Environmental Regulations”.

Increasing climate change and environmental concerns could affect the results of our operations if any of our customers request that we exceed any standard(s) set for environmentally compliant products and services. For example, we have been working on an on-going basis with our suppliers, customers, and several industry consortia to develop and provide products that are compliant with the EU “RoHS” (European Union Restriction of Hazardous Substances) Directive. Even though we are entitled to rely on various exemptions under RoHS, some of our customers might request that we provide products that exceed the legal standard set by RoHS without using any of the exemptions still permitted under RoHS. If we are unable to offer such products or offer products that are compliant, but are not as reliable due to the lack of reasonably available alternative technologies or materials, we may lose market share to our competitors.