Hsinchu, Taiwan, January 10, 2021 - UMC (TWSE: 2303, NYSE: UMC) today reported the status of its operations following abnormalities in its power supply that affected its Fabs 8A and 8CD on the afternoon of January 9.

Summary of Incident:
At 1:33pm on January 9, an abnormality caused a power outage in UMC's Gas Insulated Switchgear (GIS) equipment that services its Fabs 8A and Fab 8CD in Hsinchu, leading to a short-term electrical interruption for those fabs. After the incident, the company immediately started emergency response procedures and has since been resuming to production.

Current Status:
(1) All UMC personnel are safe and equipment operation is back to normal.
(2) Fabs 8A and 8CD are continuing to resume to full operations.
(3) There will be no significant impact on UMC's overall financial situation.
(4) The company and a small number customers may encounter adjustments to wafer shipment dates; UMC will closely monitor the situation and update the latest shipment status to customers accordingly if this happens.