EXHIBIT 15

Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C. 20549

Commissioners:

        We are aware that our report dated October 18, 2004 on our review of interim consolidated financial information of 3M Company and Subsidiaries (the "Company") for the three- and nine-month periods ended September 30, 2004 and 2003, and included in the Company's Form 10-Q for the quarter ended September 30, 2004 is incorporated by reference in the Company's Post-Effective Amendment No. 7 to the Registration Statement on Form S-3, for the registration of $639,000,000 aggregate principal amount of the Company's Liquid Yield Option(TM) Notes due 2032 (the "LYONs") and the shares of common stock of the Company issuable upon conversion of the LYONs.

Minneapolis, Minnesota
November 5, 2004