A pattern forming method, includes: (i) forming a film from a chemical amplification resist composition that contains (A) a resin capable of increasing a polarity of the resin (A) to decrease a solubility of the resin (A) for a developer containing an organic solvent by an action of an acid, (B) a compound capable of generating an acid upon irradiation with an actinic ray or radiation, and (C) a solvent; (ii) exposing the film; and (iii) performing development by using a developer containing an organic solvent, wherein the resin (A) has a structure in which a polar group is protected with a leaving group capable of decomposing and leaving by an action of an acid, and the leaving group contains a fluorine atom.