TSMC in Japan: What Is JASM, the Kumamoto Chip Plant?

Most of TSMC’s chip plants are in Taiwan, but it also runs plants in the United States, China and Japan, and is building one in Germany. Its Japanese plant belongs to Japan Advanced Semiconductor Manufacturing, or JASM, a company TSMC set up in December 2021 in Kikuyo, Kumamoto Prefecture, on Kyushu. TSMC calls JASM its “majority-owned manufacturing subsidiary,” and lists the plant as Fab 23.

Who owns JASM?

TSMC holds most of it; three Japanese companies hold the rest. Sony Semiconductor Solutions joined at the start with a stake of “less than 20%,” Denso followed in 2022 with “a more than 10%” stake, and Toyota joined in 2024 when the four companies announced a second fab. They said that after that investment the stakes would be:

Owner	Planned stake (announced February 6, 2024)
TSMC	about 86.5%
Sony Semiconductor Solutions	about 6.0%
Denso	about 5.5%
Toyota	about 2.0%

Japan’s industry ministry describes those as the stakes once the investments are complete. TSMC’s 2025 annual report puts its own stake at “approximately 72.6%” as of February 28, 2026, and its financial statements show 73% at the end of June 2026. JASM itself is not listed; TSMC trades in Taipei as 2330 and in New York as TSM, explained in TSM vs 2330.

What does the first fab make?

Logic chips on mature and specialty processes rather than TSMC’s newest ones. When TSMC announced the plant in 2021 it planned “22/28-nanometer processes”; in 2022 it added “12/16 nanometer FinFET process technology” and raised planned capacity to 55,000 12-inch wafers a month. Construction began in April 2022 and, according to TSMC, “volume production commenced in December 2024.” TSMC’s annual report lists the most advanced process in volume production at Fab 23 as 28 nanometers at the end of 2025.

Japan’s industry ministry, which approved the plan, lists the plant’s main products as logic chips on 22/28nm and 12/16nm, its capacity as 55,000 wafers a month, and its customers as mainly Japanese (“日本の顧客が中心”). TSMC called Sony “our long-time customer” when the plant was announced. The companies do not list JASM’s other customers.

What about the second fab?

It is bigger, and its plan has changed:

	First fab	Second fab
Ministry approval	June 17, 2022	February 24, 2024
Maximum subsidy	¥476.0 billion	¥732.0 billion
Investment in the approved plan	about US$8.6 billion	about US$13.9 billion (US$12.2 billion excluding 40nm)
Processes in the approved plan	22/28nm, 12/16nm	6nm, 12nm and 40nm (40nm not subsidized)
Capacity in the approved plan	55,000 wafers a month	48,000 a month (63,000 with 40nm)
First shipments	December 2024	October to December 2027 in the approved plan

Figures are 12-inch wafers and come from the ministry’s approvals and its October 2025 policy overview. TSMC said in February 2024 that with both fabs the Kumamoto site would offer “more than 100,000 12-inch wafers per month” and that the overall investment in JASM would “exceed US$20 billion.”

The plan has since moved toward newer technology. TSMC’s annual report says construction of the second fab began in October 2025, and on its October 15, 2026 earnings call TSMC said: “In Japan, we are progressing well to our plan to utilize 3-nanometer in our second fab and volume production is scheduled in 2028.” The ministry’s published approval still lists 6nm and 12nm. What Do 3nm and 2nm Mean? explains what those numbers stand for.

How big is JASM inside TSMC?

Small for now. TSMC’s capacity passed 17 million 12-inch-equivalent wafers in 2025, while the first Kumamoto fab was planned for 55,000 a month, or about 660,000 a year. In the first half of 2026, JASM made a net profit of NT$1.68 billion, according to TSMC’s financial statements. TSMC reports the subsidies it receives in Japan, the US, Germany and China together; across all of them it received NT$76.26 billion in government grants in 2025.

Why does it matter for Japan?

Japan’s industry ministry says the project contributes to “stable production of advanced semiconductors in Japan” and to reviving the country’s chip industry (our translation). Its approval also records that JASM aims to buy wafers mainly from Japanese suppliers and more than 50% of its indirect materials from local suppliers, and to hire about 1,200 people locally for each fab. Japan’s place in the chip supply chain, as a supplier of tools and materials to plants like this one, is covered in Where Japan Fits in the Chip Supply Chain.

For TSMC, JASM is one of several plants it is building outside Taiwan, with local partners and government money. For how TSMC fits next to the chip designers and other manufacturers, see Foundry, Fabless and IDM and Taiwan’s Chip Stocks: Who Makes What.