A pattern forming method comprising (i) a step of forming a film from a chemical amplification resist composition, (ii) a step of exposing the film, and (iii) a step of developing the exposed film by using an organic solvent-containing developer, wherein the resist composition contains (A) a resin capable of increasing the polarity to decrease the solubility for an organic solvent-containing developer by the action of an acid, (B) at least one kind of a compound capable of generating a sulfonic acid represented by the specific formula upon irradiation with an actinic ray or radiation, and (C) a solvent.