A positive resist composition comprising: a resin which increases solubility in an alkali developing solution by an action of an acid and comprises a repeating unit containing a lactone structure and a cyano group and a repeating unit containing a first acid-decomposable group; a resin which increases solubility in an alkali developing solution by an action of an acid and comprises a repeating unit containing a lactone structure and a cyano group and a repeating unit containing a second acid-decomposable group which is different from the first acid-decomposable group; a compound which generates an acid upon irradiation of an actinic ray or a radiation; and a solvent.