A salt represented by the formula (I0):wherein Q1 and Q2 each independently represent a fluorine atom or a C1-C6 perfluoroalkyl group, L1 represents a divalent C1-C17 hydrocarbon group in which one or more —CH2— can be replaced by —O— or —CO—, m represents 1 or 2, and Zm+ represents m-valent organic or inorganic cation.