An object of the present invention is to develop a protecting group, which can prevent solidification or insolubilization of a compound by protecting a functional group to achieve easy separation and purification after a reaction.A diphenylmethane compound represented by general formula (1): wherein Y represents —OR19 (wherein R19 represents a hydrogen atom or an active ester-type protecting group), —NHR20 (wherein R20 represents, for example, a hydrogen atom, a C1-6 linear or branched alkyl group, or an aralkyl group, at least one of R1 to R10 represents a group represented by formula (2): —O—O—R11—X-A  (2) and the others each independently represent a hydrogen atom, a halogen atom, a C1-4 alkyl group, or a C1-4 alkoxy group; R11 represents a C1-16 linear or branched alkylene group; X represents O or CONR21 (wherein R21 represents a hydrogen atom, or a C1-4 alkyl group; and A represents, for example, a group represented by formula (3).