A positive resist composition, includes: (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation; (B) a resin of which solubility in an alkali developer increases under an action of an acid; (C) a compound capable of decomposing under an action of an acid to generate an acid; and (D) a compound which itself acts as a base for the acids generated from the component (A) and the component (C) but decomposes upon irradiation with actinic rays or radiation to lose a basicity for the acids generated from the component (A) and the component (C).