To increase the maximum current density while reducing the voltage, to unify the anode current density, and to suppress the deforming the anode.

In the case of forming a main body 2 of the anode 1, a columnar copper core 4 is prepared, knurled or form-rolled to harden the surface thereof and increase the surface area, then a hollow cylindrical lead alloy 5 formed in a shape adaptable to the shape of the copper core 4 is prepared, the copper core 4 is inserted in a hollow part of the lead alloy 5 and tightly adapted thereto, and pressed by a rolling machine or a press. A hooking part 3 is brazed or welded to the copper core 4 in order to fit the hooking part 3 to an upper end of the body 2, and the copper core 4 is coated by the nickel plating.