UMC Important Notice

Taipei, Taiwan, R.O.C. - August 27, 2008 - On the afternoon of Aug. 27th, the Hsinchu District Prosecutor's Office visited UMC's offices. According to the documents provided by the staff of the Hsinchu District Prosecutors Office, this investigation is related to alleged personal investment in shares of ProMos Technologies by a single individual associated with UMC, and is not directed specifically at UMC itself and has had no material influence on the operation of the company. UMC is unaware of inappropriate activities that might constitute violation of any applicable regulations, and as of today, the investigators have not found any evidence to suggest otherwise.

Currently, UMC is fully cooperating with the prosecutor's office to clarify and misunderstandings, and is confident that the company's financial activities and investment decisions, as always, comply with applicable rules and regulations. UMC believes the decision to investigate the company is extremely regrettable and hopes to bring this incident to closure in the shortest time possible.

About UMC
UMC (NYSE: UMC, TSE: 2303) is a leading global semiconductor foundry that manufactures advanced system-on-chip (SoC) designs for applications spanning every major sector of the IC industry. UMC's SoC Solution Foundry strategy is based on the strength of the company's advanced technologies, which include production proven 90nm, 65nm, 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.