To provide an optical film which has satisfactory adhesiveness between a cellulose acetate film and an alignment film layer and can provide a preferable optical characteristic without injuring a surface state of the cellulose acetate film, with respect to the optical film provided with the alignment film layer and an optically anisotropic layer in which liquid crystalline molecules are fixed, on the cellulose acetate film, and to provide a manufacturing method of the optical film.

The manufacturing method of the optical film comprises: a process of irradiating the surface of the cellulose acetate film with electron beams so that the contact angle of water dropped onto the surface comes to 50 or less; a process of forming the alignment film layer on the treated cellulose acetate film; and a process of forming the optically anisotropic layer comprising a liquid crystal compound on the alignment film layer.