EXHIBIT 24



POWER OF ATTORNEY



Known all by these present, that the undersigned hereby constitutes and
appoints each of Michael R. Putnam and Jeffrey S. Brown, or either of
them signing singly, and with full power of substitution, the
undersigned's true and lawful attorney-in-fact to:


(1)	prepare, execute in the undersigned's name and on the
undersigned's behalf, and submit to the U.S. Securities and Exchange
Commission (the "SEC") a Form ID, including amendments thereto, and any
other documents necessary or appropriate to obtain codes and passwords
enabling the undersigned to make electronic filings with the SEC of
reports required by Section 16(a) of the Securities Exchange Act of
1934 or any rule or regulation of the SEC;


(2)	execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director of ManTech
International Corporation (the "Company"), Forms 3, 4, and 5 in
accordance with Section 16(a) of the Securities Exchange Act of 1934
and the rules thereunder;


(3)	do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete and execute
any such Form 3, 4, or 5, complete and execute any amendment or
amendments thereto, and timely file such form with the SEC and any
stock exchange or similar authority; and


(4)	take any other action of any type whatsoever in connection with
the foregoing which, in the opinion of such attorney-in-fact, may be of
benefit to, in the best interest of, or legally required by, the
undersigned, it being understood that the documents executed by such
attorney-in-fact on behalf of the undersigned pursuant to this Power of
Attorney shall be in such form and shall contain such terms and
conditions as such attorney-in-fact may approve in such attorney-in-
fact's discretion.


         The undersigned hereby grants to each such attorney-in-fact
full power and authority to do and perform any and every act and thing
whatsoever requisite, necessary, or proper to be done in the exercise
of any of the rights and powers herein granted, as fully to all intents
and purposes as the undersigned might or could do if personally
present, with full power of substitution or revocation, hereby
ratifying and confirming all that such attorney-in-fact, or such
attorney-in-fact's substitute or substitutes, shall lawfully do or
cause to be done by virtue of this power of attorney and the rights and
powers herein granted.  The undersigned acknowledges that the foregoing
attorneys-in-fact, in serving in such capacity at the request of the
undersigned, are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 of the
Securities Exchange Act of 1934.


       	This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms 3, 4, and 5
with respect to the undersigned's holdings of and transactions in
securities issued by the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the foregoing attorneys-
in-fact.


       	IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed as of this 8th day of June, 2005.


	/s/ Mary K. Bush
	_____________________
		Signature


        Mary K. Bush
         Print Name