N-CSR Item 12(b) - Exhibits: Certifications

                          SECTION 906 CERTIFICATION

Pursuant to 18 U.S.C.ss.  1350, the undersigned  officers of Federated Municipal
Securities  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
September  30, 2004 (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:  November 24, 2004

/s/ J. Christopher Donahue

Title: President, Principal Executive Officer



Dated:  November 24, 2004

/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.