For control of crystal grain size in a spin-valve film, a lithographic technique is needed which exhibits high productivity and enabling formation of a pattern at about 10 nm. In one embodiment of the invention, a diblock copolymer comprising polystyrene (PS) and polymethyl methacrylate (PMMA) is applied to a lower gap layer. When a liquid agent formed by mixing PS and PMMA is coated, a film structure comprising a sea-like PS tissue portion and an island-like PMMA tissue portion is obtained. By applying an ozone RIE treatment to the film structure, the sea-like PS tissue portion is etched to form a pattern of the island-like PMMA tissue portion. The lower gap layer is etched by using the island-like PMMA tissue portion as a resist, then the resist is removed, and an unevenness pattern arranged regularly on the lower gap layer can be formed. A spin-valve film is formed on the lower gap layer subjected to the unevenness fabrication.