CAPEX spending in 1Q23 totaled US$998 million. 2023 cash-based CAPEX budget will be US$3.0 billion.

Second Quarter 2023 Outlook & Guidance

Quarter-over-Quarter Guidance:

• Wafer Shipments: To remain flat
• ASP in USD: To remain flat
• Gross Profit Margin: Will be in the mid-30% range
• Capacity Utilization: low-70% range
• 2023 CAPEX: US$3.0 billion

Recent Developments / Announcements

Please visit UMC’s website for further details regarding the above announcements

Conference Call / Webcast Announcement

Wednesday, April 26, 2023

Time: 5:00 PM (Taipei) / 5:00 AM (New York) / 10:00 AM (London)

A live webcast and replay of the 1Q23 results announcement will be available at www.umc.com under the “Investors / Events” section.

About UMC

UMC (NYSE: UMC, TWSE: 2303) is a leading global semiconductor foundry company. The company provides 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. UMC has total 12 fabs in production with combined capacity of approximately 850,000 8-inch equivalent wafers per month, and all of them are certified with IATF 16949 automotive quality standard. Most of UMC's 12-inch and 8-inch fabs with its core R&D are located in Taiwan, with additional ones throughout Asia. UMC is headquartered in Hsinchu, Taiwan, plus local offices in China, United States, Europe, Japan, Korea and Singapore, with worldwide total 20,000 employees. For more information, please visit: https://www.umc.com.

Safe Harbor Statements

This press release contains forward-looking statements within the meaning of Section 27A of the United States Securities Act of 1933, as amended, and Section 21E of the United States Securities Exchange Act of 1934, as amended, and as defined in the United States Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to, statements regarding anticipated financial results for the first quarter of 2023; the expected wafer shipment and ASP; the anticipated annual budget; capex strategies; environmental protection goals and water management strategies; impact of foreign currency exchange rates; expected foundry capacities; the ability to obtain new business opportunities; and information under the heading “First Quarter of 2023 Outlook and Guidance.”