A method of forming an inorganic alignment film on a base substrate is provided comprising forming a film made substantially of an inorganic material on the base substrate, and irradiating ion beams onto the surface of the film from a direction inclined at a predetermined angle .theta..sub.b with respect to the direction vertical to the surface. By irradiating the ion beams onto the film, concave portions having a predetermined directivity are formed on the film. The predetermined angle .theta..sub.b is preferably 2.degree. or more.