The present invention provides a salt of the formula (I): ##STR00001## wherein ring X represents polycyclic hydrocarbon group having tricycle or more and having 10 to 30 carbon atoms, and one or more hydrogen atom in the ring X is optionally substituted with alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, perfluoroalkyl group having 1 to 4 carbon atoms or cyano group; Q.sup.1 and Q.sub.2 each independently represent fluorine atom or perfluoroalkyl group having 1 to 6 carbon atoms; n shows an integer of 1 to 12; and A.sup.+ represents a cation selected from the group consist of a cation of the following formulae (IIa), (IIb) and (IIc): ##STR00002## The present invention also provides a chemically amplified resist composition comprising the salt of the formula (I).