A method for producing a clay thin film, which is formed of clay alone or in combination with an additive and has a structure where oriented clay particles are laminated, the method including paste-making in which clay alone or in combination with an additive are dispersed in a dispersion medium formed of water, an organic solvent, or a mixed solvent of water and an organic solvent to prepare clay paste; coating in which a thin film is formed by coating the clay paste on a substrate; planarization in which the thin film is planarized; drying in which water, an organic solvent, or water and an organic solvent are removed from the thin film; and separation in which the thin film is separated from the substrate.