A semiconductor device includes at least three or more wiring layers stacked in an interlayer insulating film on a semiconductor substrate, a seal ring provided at the outer periphery of a chip region of the semiconductor substrate and a chip strength reinforcement provided in part of the chip region near the seal ring. The chip strength reinforcement is made of a plurality of dummy wiring structures and each of the plurality of dummy wiring structures is formed to extend across and within two or more of the wiring layers including one or none of the bottommost wiring layer and the topmost wiring layer using a via portion.