A semiconductor device includes a base, a semiconductor element having a plurality of electrodes, a plurality of conductive lines connected to the electrodes of the semiconductor element, plating stubs attached to the conductive lines, and a plurality of wiring layers formed in a plurality of layers on the base. The plating stub attached to a first conductive line, and the plating stubs attached to one or a plurality of second conductive lines adjacent to the first conductive line, exist in different conductive wiring layers.