An apparatus that performs an electrolytic plating on a plating surface of a belt substrate is provided. The apparatus includes a plating tank, a conveyor device configured to carry a belt substrate through an interior of the plating tank, an immersed cathode power-supply section provided within the interior of the plating tank, an auxiliary cathode power-supply section provided within the interior of the plating tank, and short-circuit wiring configured to short-circuit the immersed cathode power-supply section to the auxiliary cathode power-supply section. A plating method for performing electrolytic plating on a plating surface of a belt substrate is provided. The method includes conveying the belt substrate through a plating tank, making the plating surface a cathode by contacting at least one of an immersed cathode power-supply section or an auxiliary cathode power-supply section with the belt substrate, and short-circuiting the immersed cathode power-supply section to the auxiliary cathode power-supply section.