In a semiconductor device, a substrate includes a plurality of line conductors which penetrate the substrate from a top surface to a bottom surface of the substrate. A semiconductor chip is secured in a hole of the substrate. A first insulating layer is formed on the top surfaces of the substrate and the semiconductor chip. A first wiring layer is formed on the first insulating layer and electrically connected via through holes of the first insulating layer to the semiconductor chip and some line conductors exposed to one of the through holes. A second insulating layer is formed on the bottom surfaces of the substrate and the semiconductor chip. A second wiring layer is formed on the second insulating layer and electrically connected via a through hole of the second insulating layer to some line conductors exposed to the through hole.