The purpose of the present invention is to provide a plating jig, which is capable of forming metal plating films at the same time on both the surfaces of a semiconductor wafer by performing plating one time, and which has a simple configuration with a thinner holding section. This plating jig is provided with: a base section and a cover section, which are formed such that the sections can hold a substrate to be plated; and a center section, which is sandwiched between the base section and the cover section, and which aligns the substrate to be plated. The plating jig is characterized in that: each of the base section, the cover section, and the center section has an annular portion having an opening at the center; to each of the facing surfaces of the base section annular portion and the cover section annular portion, a seal packing having a conductive ring disposed thereon is attached; the substrate to be plated is disposed in the opening of the center section; and the substrate to be plated is sandwiched from both the front and rear surfaces by means of the seal packing attached to each of the cover section and the center section.