Abstract: The present invention provides a method for formation of a siliceous film containing nitrogen in a low concentration. The method according to the present invention comprises the steps of: applying a polysilazane composition on an engraved substrate surface, to form a coating layer; hardening the coating layer only in the part adjacent to the substrate surface, to form a covering film along the shape of the engraved substrate; and removing the polysilazane composition of the coating layer in the part not hardened in the above covering film-formation step. According to this method, two or more siliceous films can be formed and layered.