A salt represented by formula (I): wherein R1 and R2 independently represent a hydrogen atom, a hydroxy group or a C1 to C12 hydrocarbon group in which a methylene group may be replaced by a —O— or —CO—; m and n independently represent 1 or 2; Ar represents an optionally substituted phenyl group; Q1 and Q2 independently represent a fluorine atom or a C1 to C6 perfluoroalkyl group, A1 represents a single bond, a C1 to C24 alkanediyl group or the like, and Y represents an optionally substituted C1 to C18 alkyl group or monovalent C3 to C18 alicyclic hydrocarbon group, and a methylene group therein may be replaced by a —O—, O— or —SO2—, provided that the alkyl group or the alicyclic hydrocarbon group has at least one substituent, or at least one methylene group contained therein is replaced by a —O—, —CO— or —SO2—.