UMC Receives Top Award for Sustainable Development from
the ROC Government's Executive Yuan

Hsinchu, Taiwan, June 3, 2005 -- UMC, a world leading semiconductor foundry, was awarded first place in the competition for the "Sustainable Enterprise Award" by the Republic of China's (Taiwan) Executive Yuan. This honor is awarded annually to recognize organizations that contribute to the cause of sustainable development in Taiwan.

The awards are given to honor candidates in five categories: communities, schools, enterprises, non-government organizations, and government agencies. The event is divided into preliminaries, semifinals, and finals. In the semifinals, the judges pay on-site visits to all the organizations, where they conduct inspections and review meetings and are briefed by the organizations' representatives. In the finals, winners are chosen after deliberation among the judges.

UMC was the top recipient in the enterprise category based on its outstanding performance in 4 areas: environmental and resource conservation, management principles and performance, Technical R&D, and contribution to sustainable development. The exemplary performance of the recipients is highlighted by the Executive Yuan to encourage others to join in sustainable development efforts.

Dr. Jackson Hu, CEO of UMC, said, "We are extremely honored to receive this award from the government's executive body. The award is a highly appreciated testament to the efforts we have made over the years to make UMC a model corporate citizen in Taiwan. Everyone at UMC should be proud that we have been singled out as a model for others for an award that measures corporate activities in such a comprehensive manner. We constantly strive for best practices in environmental protection, technology development and management."

About the Sustainable Development Award
The UN introduced the concept of sustainable development in the 1980s based upon the three pillars of environmental protection, economic development, and social justice. Sustainable development has now become a common goal for countries around the world. To effectively carry out sustainable development, the Executive Yuan in 1997 established the National Council for Sustainable Development, whose tenets include protecting the environment, ensuring social fairness and justice, promoting economic development, and establishing a green silicon island. The Taiwan Sustainable Development Award is conducted so as to recognize organizations that contribute to the cause of sustainable development.

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 Fab 12i are both in volume production for a variety of customer products. UMC employs approximately 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.

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