A positive resist composition comprising: at least one compound selected from a compound capable of generating an acid represented by the formula (I) as defined herein upon irradiation with actinic rays or radiation and a compound capable of generating an acid represented by the following formula (II) upon irradiation with actinic rays or radiation; and a compound capable of generating an acid represented by the formula (III) as defined herein upon irradiation with actinic rays or radiation.