1934 Act Registration No. 1-14700

SECURITIES AND EXCHANGE COMMISSION

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16 OF
THE SECURITIES EXCHANGE ACT OF 1934

For the month of June 2005

Taiwan Semiconductor Manufacturing Company Ltd.

No. 8, Li-Hsin Rd. 6,
Hsinchu Science Park,
Taiwan
(Address of Principal Executive Offices)

     (Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.)

     (Indicate by check mark whether the registrant by furnishing the information contained in this form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.)

(If “Yes” is marked, indicated below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82:                     .)

TSMC Announce May 2005 Sales and Revise Upward 2Q2005 Guidance

Hsinchu, Taiwan, R.O.C. – June 9, 2005 — TSMC (TAIEX: 2330, NYSE: TSM) today announced that net sales for May 2005 totaled NT$19,508 million, and that revenues for January through May 2005 were NT$94,064 million.

Ms. Lora Ho, TSMC vice president and chief financial officer, noted that, “Due to higher wafer shipments, net sales for May 2005 increased by 3.2 percent compared to April 2005. On a year-over-year basis, net sales for May 2005 decreased 10.2 percent.”

“Due to demand recovery from our customers, we therefore revised upward our second quarter guidance with respect to the following items: wafer shipment will increase by a low double digit percentage point, overall utilization rate will be about 84%, and gross profit margin will be about 40%, which is at the high end of our initial guidance,” Ms. Ho added.

Sales Report:

TSMC Spokesperson:

Ms. Lora Ho
Vice President and CFO
Tel: 886-3-566-4602

TSMC Acting Spokesperson:

Mr. J.H. Tzeng
PR Department Manager, TSMC
Tel: 886-3-666-5028
Mobile: 0928-882607
Fax: 886-3-567-0121
E-Mail: jhtzeng@tsmc.com

For further information, please contact:

Richard C.Y. Chung
Media Relations Manager, TSMC
Tel: 886-3-666-5038
Mobile: 886-911-258751
Fax: 886-3-567-0121
E-Mail: cychung@tsmc.com

Taiwan Semiconductor Manufacturing Company Limited

June 09, 2005

This is to report the changes or status of 1) sales volume, 2) funds lent to other parties, 3) endorsements and guarantees for the period of May 2005.

1) Sales volume (in NT$: thousand)

2) Funds lent to other parties (in NT$: thousand)

3) Endorsements and guarantees (in NT$: thousand)

Taiwan Semiconductor Manufacturing Company Limited

June 09, 2005

This is to report the financial derivative transactions for the period of May 2005.

Hedging purpose (for assets / liabilities denominated in foreign currencies)

SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.