With the damascene process in which an interconnection is formed using a conventional chemically amplified positive photoresist composition, there arises a problem that the photoresist within the via hole (as well as in its vicinity) may remain even after the exposure and the development are carried out. The present invention relates to a chemically amplified resist composition comprising, at least, a photo acid generator, a quencher and a salt having a buffering function for an acid which is generated from the acid generator by irradiation, wherein the salt having the buffering function for the acid generated from the acid generator is a salt derived from a long chain alkylbenzenesulfonic acid or a long chain alkoxybenzenesulfonic acid and an organic amine that is a basic compound.