A processed product is continuously partially plated without being covered. Electroplating is carried out on a portion other than a head of a processed product also having a lower part and a constricted part between the head and the lower part. A pair of rails has an opening between the rails narrower than the head and broader than the constricted part, and electrodes are arranged thereon. A plating bath is positioned below the rails, and electrode plates are arranged in a plating solution. The constricted part of the processed product is positioned at the opening between the rails, and a pushing element extending from above the rails through the opening contacts the processed product at a position lower than the center of gravity at the lower part. The pushing element is displaced along the rails to plate a portion of the processed products positioned below the rails.