Exhibit 24




						  POWER OF ATTORNEY



	    KNOW ALL
MEN BY THESE PRESENTS: That the undersigned has made,
constituted and
appointed, and by this instrument does make, constitute and
appoint
ROBERT PIERCE, ELIZABETH SHAUGHNESSY and CIPRIANO BEREDO, acting

individually, as his or her true and lawful attorney, for him or her, and
in his
or her name, place and stead, to affix, as attorney-in-fact, the
signature of
the undersigned to any reports or filings to the Securities
and Exchange
Commission on or in connection with Forms 3, 4, 5 or 144
with respect to
transactions or holdings by the undersigned in equity
securities issued by OM
Group, Inc., a Delaware corporation, and to any
and all amendments to such
reports, giving and granting unto each such
attorney-in-fact full power and
authority to do and perform every act and
thing whatsoever necessary to be done
in the premises, as fully as the
undersigned might or could do if personally
present, hereby ratifying and
confirming all that each such attorney-in-fact
shall lawfully do or cause
to be done by virtue hereof.

		This Power of Attorney shall expire on
the date the undersigned is no
longer required to file Forms 3, 4, 5 or
144 reports with the Securities and
Exchange Commission with respect to
holdings of and transactions in securities
issued by OM Group, Inc.,
unless revoked in writing prior thereto.

		IN WITNESS WHEREOF, this
Power of Attorney has been signed at Key
Tower, Cleveland, Ohio, as of
the 16th day of February, 2006.




									 /s/ Daniel K.
Lewis
							    --------------------------------
									   Daniel
K. Lewis