In a semiconductor device, a conductor pattern is disposed in a position overlapped by a semiconductor chip in a thickness direction over the mounting surface (lower surface) of a wiring board. A solder resist film (insulating layer) covering the lower surface of the wiring board has apertures formed such that multiple portions of the conductor pattern are exposed. The conductor pattern has conductor apertures. The outlines of the apertures and the conductor apertures overlap with each other, in a plan view, respectively.