UMC is best known for its high quality IC fabrication services, focusing on logic and various specialty technologies to serve all major sectors of the electronics industry. UMC’s comprehensive IC processing technologies and manufacturing solutions include Logic/Mixed-Signal, embedded High-Voltage, embedded Non-Volatile-Memory, RFSOI and BCD etc.

Most of UMC's 12-in & 8-in fabs with its core R&D are located in Taiwan, with additional ones throughout Asia. UMC has total 12 fabs in production with combined capacity close to 800,000 wafers per month (8-in equivalent), and all of them are certified with IATF-16949 automotive quality standard.

UMC has local offices in the United States, Europe, China, Japan, Korea and Singapore, with a total of 20,000 employees worldwide.

The company's milestones:

- In 1980: UMC was spun off from the Industrial Technology Research Institute and was formally established as the first private integrated circuit company in Taiwan.

- In 1985: UMC was officially listed on the Taiwan Stock Exchange (code: 2303). It was the first listed semiconductor company in Taiwan.

- In 1995: UMC decided to transform from an IDM company with its own products to a professional pure-play foundry.

- In 1996: Spun off its IC design units to establish MediaTek, Novatek, ITE Technology, Faraday Technology, AMIC Technology, and Davicom.

- In 1998: Acquired Holtek Semiconductor fab and Nippon Steel Semiconductor Corp. fab.

- In 1999: Begins construction of 300mm fab in Taiwan's Tainan Science Park, Fab 12A.

- In 2000:

Lists on the New York Stock Exchange (code: UMC) as Taiwan's first semiconductor company to do so.

Produces the first chips using copper process technology and the first 0.13 micron ICs in the semiconductor industry.

- In 2004:

Completes acquisition of SiS Microelectronics Corp. fab.

12-inch wafer fab in Singapore enters mass production.

- In 2006: Becomes first IC company to achieve QC 080000 IECQ HSPM qualification for all fabs.

- In 2008: UMC announced foundry industry's first 28nm SRAMs.

- In 2009: Fully acquired Japan subsidiary UMCJ.

- In 2010: Fab 12A Phase3 enters volume production.

- In 2011: UMC enters 28nm pilot production

- In 2013: UMC acquired Hejian fab based in Suzhou, China

- In 2015: USCXM 12-inch wafer fab located in Xiamen, Fujian Province, China was officially established.

- In 2017: 28 nm mass production begins at USCXM in Xiamen, China.

- In 2019: Fully acquired Japan-based Mie Fujitsu Semiconductor.

- In 2022: UMC announced expansion of Fab 12i in Singapore (P3 facility)

According to en.wikipedia.org, umc.com