Hsinchu, Taiwan, March 14, 2011 - UMC announced today details regarding the financial and business impact on the Company from the earthquake in Japan that occurred on March 11th, 2011. UMC owns one 8-inch fab in Japan, UMC Japan (UMCJ). The subsidiary company is located at Tateyama City, Chiba, where the magnitude of the overall 9.0 earthquake was measured as a 5.0 for that area. All employees were successfully evacuated and there was no one injured at UMCJ. UMCJ's capacity represents 3~5% of UMC's total capacity and there was no damage to production equipment. The facility is currently undergoing equipment calibration. As such, there is no material financial or business impact to UMC.

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.

UMC JAPAN (UMCJ), Japan's first and only dedicated-silicon foundry, provides advanced technologies and semiconductor manufacturing on a contractual basis. The company is a subsidiary of UMC. UMCJ can be found at http://www.umcj.com/english.