To suppress peeling off of a polymer coating in a polymer member formed to have the polymer coating provided on a surface of a polymer shaped object, performed are: a curing step of causing a curable composition to be cured by energy rays to prepare the polymer shaped object; a coating step of forming the polymer coating on the polymer shaped object; and a post-curing step of irradiating the polymer shaped object with the energy rays after the coating step, wherein, in the curing step, the polymer shaped object in which a reactive functional group is left is prepared.