(a) An aerosol including an active material, a binder, and a gas is made. (b) A film-like flow of the aerosol is formed. (c) An electrically-charged region is formed by corona discharge. (d) The film-like flow passes through the electrically-charged region. (e) The film-like flow is introduced into an electric field after passing through the electrically-charged region. In the electric field, an active material layer is formed by adhering a solid component of the film-like flow onto a surface of a substrate by electrostatic force.