SECTION 906 CERTIFICATION

Pursuant to 18 U.S.C.ss.  1350, the undersigned  officers of Federated Municipal
High Yield Advantage Fund, Inc. (the "Registrant"),  hereby certify, to the best
of our  knowledge,  that the  Registrant's  Report on Form  N-CSR for the period
ended February 28, 2005 (the "Report")  fully complies with the  requirements of
Section 13(a) or 15(d),  as  applicable,  of the  Securities and Exchange Act of
1934 and that the information  contained in the Report fairly  presents,  in all
material  respects,  the  financial  condition  and results of operations of the
Registrant.


Dated: April 19, 2005

/s/ J. Christopher Donahue

Title: President, Principal Executive Officer



Dated: April 19, 2005

/s/ Richard J. Thomas

Title: Treasurer, Principal Financial Officer

This certification is being furnished solely pursuant to 18 U.S.C.ss. 1350 and
is not being filed as part of the Report or as a separate disclosure document.