The present invention provides a pharmaceutical composition comprising a combination of an Hsp 90 family protein inhibitor and at least one compound, the said pharmaceutical composition wherein the Hsp 90 family protein inhibitor is a benozoyl compound represented by formula (I):[wherein n represents an integer of 1 to 5R1 represents substituted or unsubstituted lower alkyl, CONR7R8 (wherein R7 and R8, which may be the same or different, each represent a hydrogen atom, substituted or unsubstituted lower alkyl, or the like), or the likeR2 represents substituted or unsubstituted aryl, or the likeR3 and R5, which may be the same or different, each represent a hydrogen atom, substituted or unsubstituted lower alkyl, or the likeR4 represents a hydrogen atom, hydroxy or halogen andR6 represents a hydrogen atom, halogen, substituted or unsubstituted lower alkyl, or the like], or a prodrug thereof or a-pharmaceutically acceptable salt thereof, and the like.
