A method for producing an optical film by a solution spreading film deposition method, in which a poor stripping region of a metal support can be eliminated by spreading dope on the surface of the metal support after a surface treatment film is formed on the surface of the metal support by atmospheric pressure plasma processing or excimer UV processing. Consequently, limitation on the conditions of film production is reduced and productivity is enhanced. Furthermore, since stripping of the film is enhanced, lateral variation in stripping position is reduced and variation in retardation value is reduced sharply, and thereby an optical film having optical characteristics excellent in transparency and planarity can be produced. Consequently, a method for producing an optical film, an opticalfilm, a polarizing plate and a display which can meet the demands of a high quality thin and wide protective film for polarizing plate can be provided.