HSINCHU, Taiwan, September 16, 2010 - UMC (NYSE: UMC; TSE: 2303), a leading global semiconductor foundry, today announced that Dow Jones Sustainability Index (DJSI) has scored UMC first among all semiconductor companies for total points in the environmental sector, including perfect scores in product accountability and operational eco-efficiency. This is the third consecutive year that UMC has been selected as a global component. UMC was listed for both the DJSI-World and DJSI-Asia Pacific indexes this year. DJSI-World 2010 evaluated 2,617 global enterprises, with only 318 enterprises qualifying as global components. Only seven semiconductor companies were selected worldwide.

UMC also achieved the highest scores for environmental policy/management system, stakeholder engagement and standards for suppliers. Since being listed in 2008, UMC's overall scores have increased each year. UMC's scores this year increased significantly, with expectations of UMC being upgraded to a gold enterprise from last year's silver when grading is announced later this year. This achievement demonstrates UMC’s continued world-leading sustainable performance that is highly recognized by international investors.

Dr. Shih-Wei Sun, CEO from UMC, said, "We are pleased that UMC's accomplishments in corporate sustainability have been recognized again by Dow Jones Sustainability Indexes, one of the most respected indexes worldwide. Since all selected companies in the semiconductor sector are large international companies, UMC's high scoring performance is outstanding. Going forward, we will continue to fulfill our responsibility as a corporate citizen and contribute to the environment and society, while enhancing our business competitiveness to maximize shareholder value in a more forward-looking and aggressive way. UMC will also assist our customers in producing green products to jointly improve our sustainable competitiveness."

Dow Jones Sustainability Indexes was launched jointly by Dow Jones Index, STOXX and Sustainable Asset Management (SAM) in 1999. DJSI includes global indexes, regional indexes and special indexes. Global components of DJSI are reselected every year based on the comprehensive evaluation of the performance of each enterprise in the aspects of economy, environment and society. DJSI is the first index that traces social responsibility performance of leading-edge enterprises, and is also one of the most creditable evaluation tools for reviewing sustainability worldwide. "DJSI-World" picks approximately 2,500 global enterprises for the evaluation and the top 10% of these enterprises will be listed as its components. "DJSI-Asia Pacific" picks top 600 enterprises in Asia Pacific for the evaluation, and the top 20% whose market coverage are in top 45% in this region will be listed as its components.

UMC (NYSE: UMC, TSE: 2303) is a leading global semiconductor foundry that provides advanced technology and manufacturing services for applications spanning every major sector of the IC industry. UMC's customer-driven foundry solutions allow chip designers to leverage the strength of the company's leading-edge processes, which include production proven 65nm, 45/40nm, mixed signal/RFCMOS, and a wide range of specialty technologies. Production is supported through 10 wafer manufacturing facilities that include two advanced 300mm fabs; Fab 12A in Taiwan and Singapore-based Fab 12i are both in volume production for a variety of customer products. The company employs approximately 13,000 people worldwide and has offices in Taiwan, Japan, Singapore, Europe, and the United States. UMC can be found on the web at http://www.umc.com.

Note From UMC Concerning Forward-Looking Statements
Some of the statements in the foregoing announcement are forward looking within the meaning of the U.S. Federal Securities laws, including statements about future outsourcing, wafer capacity, technologies, business relationships and market conditions. Investors are cautioned that actual events and results could differ materially from these statements as a result of a variety of factors, including conditions in the overall semiconductor market and economy; acceptance and demand for products from UMC; and technological and development risks.