The invention provides a method for producing a polymer electrolyte membrane including (A) a membrane formation step of forming a membrane-form product of an ionic group-containing polymer electrolyte on a support, (B) an acid treatment step of exchanging the ionic group into an acid type by bringing the membrane into contact with an inorganic acid-containing acidic liquid, (C) an acid removal step of removing a free acid in the acid-treated membrane, and (D) a drying step of drying the acid-removed membrane, wherein the steps (B) to (D) are carried out without separating the membrane from the support.