WEC Energy (WEC) 10-Q 2006 Q2 Quarterly report

Exhibit 32.1

Certification Pursuant to
18 U.S.C. Section 1350,
As Adopted Pursuant to
Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the Quarterly Report of Wisconsin Energy Corporation (the "Company") on Form 10-Q for the period ended June 30, 2006, as filed with the Securities and Exchange Commission on August 2, 2006 (the "Report"), I, Gale E. Klappa, as Chief Executive Officer of the Company, hereby certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, to the best of my knowledge, that:

        (1)     The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

        (2)     The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/GALE E. KLAPPA               
Gale E. Klappa
Chief Executive Officer
August 2, 2006