A technique for reducing the size of a semiconductor device is provided. A semiconductor device comprises a base, a semiconductor chip, a chip component, an insulating base, a wiring pattern, a via plug, an external lead-out electrode, a recess, and a resin. The insulating base has a multi-layer structure formed by laminating a plurality of insulator films. The semiconductor chip and the chip component are mounted on the base and embedded in the insulating base. A recess is formed on the surface of the semiconductor device and reaches down to any of wiring conductor layers. The semiconductor chip and the chip component are mounted on the recess.