To reduce an internal resistance value and improve energy density by applying the constitution that an oxide film on the surface of a conductive metallic foil be partly broken, immediately before applying paste containing an electrode-active material to the surface of the foil.

Paste 3 is applied to the surface of a copper foil 2 by use of an applicator 1 and, then the copper coil 2 is moved in an arrow B-direction under the rotation of a wire drum 4 in an arrow A-direction, thereby spreading the paste 3. The wire drum 4 is made of a bundle of a large number of brass wires, and the leading ends of right-stranded wires form a cylindrical surface, and the rotational direction thereof is made opposite to the travel direction of the copper foil 2. The wire drum 4 is thereby formed to increase a scraping force for the surface of the copper foil 2. The paste 3 is applied immediately after an oxide film on the copper foil 2 is thus broken partly. Also, irregularities are formed concurrently with the breakage of the oxide film on the copper foil 2, and the surface area of the foil 2 is increased, thereby improving output density all the more and at the same time, the adhesive strength of an electrode layer improves due to an anchoring effect. Furthermore, resistance against vibration or shock is improved.