UMC Becomes First Semiconductor Manufacturer to Achieve
QC 080000 IECQ HSPM Qualification for All Fabs

Accomplishment Signifies Foundry's Continuing Commitment to Environmentally-Friendly Business Practices

HSINCHU, Taiwan, June 13, 2006 - UMC, a leading global semiconductor foundry, today announced it has completed the final system audit for QC 080000 IECQ Hazardous Substance Process Management (HSPM) qualification to become the first semiconductor manufacturer worldwide to achieve HSPM certification. QC 080000 IECQ HSPM is the standard that the International Electrotechnical Commission (IEC) Quality Assessment System for Electronic Components (IECQ) approved for Hazardous Substance Process Management in October 2005.

"Sustainable development and environmental protection issues have become important indexes for conducting international business," said Dr. Jackson Hu, chairman and CEO at UMC. "UMC has been very successful in practicing environmentally-friendly development and sustainable-resource utilization to achieve our goal of operating as a green enterprise. We have integrated the concept of sustainable development into our core business strategy, so that two seemingly contradictory concepts, competitive business operation and environmental protection, can be harmonized for the benefit of society."

Corporations have taken extensive measures to conform to the new RoHS (Restriction of the use of certain Hazardous Substances in electrical and electronic equipment) Directive that will become effective July 2006. The RoHS Directive will ban electronic products that contain certain levels of six listed hazardous substances from entering European markets. UMC has led the semiconductor industry in sustainable, environmentally friendly development with its QC 080000 IECQ HSPM Qualification, which stringent requirements go above and beyond the six listed materials in the RoHS guidelines to include the restriction of over 20 different hazardous substances.

The completion of QC 080000 IECQ HSPM qualification audit demonstrates UMC's capabilities in managing hazardous substances and meeting RoHS Directives. This qualification assures UMC's continued access to the European markets to help its customers expand their market share. The QC 080000 IECQ HSPM standard is based on the ISO 9001:2000 quality management system, while also combining a "flow orientation" measure and systematic management process. This standard is the only green product quality management system that has been widely used and approved around the world.

About UMC's Environmental Protection Efforts
UMC began promoting its green supply chain management in 2003 as part of a larger international environmental protection trend. The company implemented standard procedures for green procurement through supplier controls and process and materials review. UMC also has materials inspections performed regularly by independent organizations to affirm strict compliance of the RoHS Directive. UMC became a SONY Green Partner in 2003 and completed its renewal audit in 2005, demonstrating positive customers recognition of UMC's efforts on hazardous substances.

UMC's years of promoting environmental protection, introducing sustainable development tools and participation in international environmental protection activities have gradually come to fruition. The World Bank Group gave official recognition to UMC's excellent environmental protection performance during its 2002 Global Summit of Sustainable Development. UMC also received the runner up award for Environmental Excellence from the Asian Institute of Management at their 2004 Asian CSR Awards. In 2006, UMC received the highest rank in a Corporate Social Responsibility Survey conducted by CommonWealth Magazine. These honors recognized UMC's efforts in promoting environmental protection, sustainable development and social responsibility in addition to pursuing business success and growth. Meanwhile, UMC was awarded several government honors such as the National Sustainable Development Award, Industrial Sustainable Excellence Award, Corporate Environmental Protection Award, Green Office Award, Water Conservation Award, Energy Saving Award, and others.

In the future, UMC will continue to improve itself based on a Plan, Do, Check, Act (PDCA) system to effectively control hazardous substances through its implementation of QC 080000 IECQ HSPM for aspect of the company's operations. UMC will transform the RoHS regulation into a green business opportunity, and fulfill the responsibility of a corporate citizen by contributing to the benefit of the environment.

About UMC
UMC (NYSE: UMC, TSE: 2303) is a leading global semiconductor foundry that manufactures advanced process ICs for applications spanning every major sector of the semiconductor industry. UMC delivers cutting-edge foundry technologies that enable sophisticated system-on-chip (SoC) designs, including 90nm copper, 0.13um copper, and mixed signal/RFCMOS. UMC is also a leader in 300mm manufacturing; Fab 12A in Taiwan and Singapore-based UMCi are both in volume production for a variety of customer products. UMC employs over 10,500 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.

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