The present invention provides a salt of the formula (I): ##STR00001## wherein X represents divalent or trivalent residue of acyclic hydrocarbon having 1 to 30 carbon atoms or divalent or trivalent residue of hydrocarbon having 3 to 30 carbon atoms which contains monocyclic or bicyclic ring, wherein --CH.sub.2-- in the hydrocarbon may be substituted with --O-- and one or more hydrogen atom in X is optionally substituted with alkoxy group having 1 to 6 carbon atoms, perfluoroalkyl group having 1 to 4 carbon atoms, hydroxyalkyl group having 1 to 6 carbon atoms, hydroxyl group or cyano group; Q.sup.1 and Q.sup.2 each independently represent fluorine atom or perfluoroalkyl group having 1 to 6 carbon atoms; A.sup.+ represents organic counter ion; Y represents hydroxyl group, cyano group or methoxy group; and n shows 1 or 2.The present invention also provides a chemically amplified resist composition comprising the salt of the formula (I).