UMC Board Approves Resignation of UMC Chairman Bob Tsao;
CEO Jackson Hu Elected to Position as Chairman

Hsinchu, Taiwan, January 9, 2006 - UMC (NYSE: UMC, TSE: 2303) today held an Extraordinary Meeting of the Board of Directors. During the meeting, the Board of Directors passed the following resolutions:

1) UMC Chairman Bob Tsao has officially resigned from his position as Chairman of the company, and the current CEO, Dr. Jackson Hu, was elected to the position of Chairman.

2) UMC Chairman Bob Tsao and Vice Chairman John Hsuan have resigned from their board positions at UMC.

3) The UMC Board has granted Bob Tsao the title of Chairman Emeritus and John Hsuan the title of Vice Chairman Emeritus and hired both as senior advisors to the company and entitled them to attend future meetings of the Board of Directors.

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 volume production 90nm, industry-leading 65nm, and mixed signal/RFCMOS. UMC's 10 wafer manufacturing facilities 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 12,000 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.