A stamper manufacturing method comprises: forming a stamper body so as to have a concave/convex pattern on one surface and a crystalline structure on at least a side toward the other surface; forming a layer having an amorphous structure on the other surface side of the stamper body; and polishing a surface of the layer having the amorphous structure. A resin molded article manufacturing method includes an injection molding process using the stamper as a prototype so as to transfer the concave/convex pattern of the stamper to a resin material. A stamper comprises a stamper body which is formed so as to have a concave/convex pattern on one surface and have a crystalline structure on at least a side toward the other surface. In the stamper, a layer having an amorphous structure and a surface of which is polished is formed on the other surface side of the stamper body.