EXHIBIT 15
October 30, 2014
Securities and Exchange Commission
100 F Street, N.E.
Washington, DC 20549
Commissioners:
We are aware that our report dated October 30, 2014 on our review of interim financial information of 3M Company and its subsidiaries for the three and nine month periods ended September 30, 2014 and 2013 and included in the Companys quarterly report on Form 10-Q for the quarter ended September 30, 2014 is incorporated by reference in its Registration Statement on Form S-8 (Registration Nos. 333-30689, 333-30691, 333-44760, 333-73192, 333-101727, 333-101751, 333-109282, 333-128251, 333-130150, 333-151039, 333-156626, 333-156627, 333-166908, 333-174562, 333-181269, and 333-181270) and Form S-3 (Registration Nos. 333-196003, 33-48089, 333-42660, and 333-109211).
Very truly yours,
/s/ PricewaterhouseCoopers LLP
PricewaterhouseCoopers LLP