PURPOSE: To charge an electric car, etc., by converting AC to DC with a jumbo diode composed of the three layers of aluminum-arsenic-aluminum, or jumbo diode composed of a mixed metal obtained by mixing aluminum and arsenic in a specified ratio.

CONSTITUTION: A diode is formed by putting an arsenic thin board 2 between the upper and lower aluminums 1 and by attaching them. The upper and lower aluminums 1 have a cylindrical shape of a diameter of 2m and a height of 1.5m respectively, and the arsenic thin board 2 put between them has a diameter of 2m and a thickness of 1μ, and they are attached together in series to form a jumbo diode 3. Or a jumbo diode 3 is formed by mixing aluminum and arsenic uniformly in a mixing ratio of n:1 (n≥101) to obtain a metal 4, and by forming the metal 4 into a columnar shape with a diameter of 2m and a height of 3m. Consequently, it becomes possible to constitute an electric station capable of charging batteries for electric cars efficiently.