The present invention is a positive type resist composition comprising a resin component (A) for use in a resist, having alkali solubility which increases under the action of an acid, an acid generator component (B) which generates an acid upon being exposed, and an organic solvent which dissolves the resin component (A) and the acid generator component (B), wherein the resin component (A) contains the resin component (A1) for use in a resist having alkali solubility which increases under the action of an acid having the following structural units (a1), (a2) and (a3): structural unit (a1): a structural unit derived from an (α-lower alkyl) acrylic ester which contains acid-dissociable, dissolution-inhibiting groups expressed by the following general formula (1): [chemical formula 1] (in formula (1), R represents a hydrogen atom or a lower alkyl group, R11represents acid-dissociable, dissolution-inhibiting groups consisting of chain tertiary alkyl groups), structural unit (a2): a structural unit derived from an (α-lower alkyl) acrylic ester which contains lactone-containing monocyclic or polycyclic groups, structural unit (a3): a structural unit derived from an (α-lower alkyl) acrylic ester which contains polycyclic and alicyclic hydrocarbon groups which contain polar groups.