A technique for mounting a plurality of electronic parts on one surface of a wiring substrate is provided. A semiconductor device comprises a wiring substrate having connection pads disposed outside a parts mount; a plurality of electronic parts with the first surface having a plurality of electrodes and the second surface fixing; a first underlying insulation layer provided between the connecting pads and the electrodes; a first metal layer formed overlaid on the first underlying insulation layer and providing connections between the connecting pads and the electrodes; a second underlying insulation layer having electrically insulating properties, provided between the respective electrodes of adjacent electronic parts; a second metal layer formed overlaid on the second underlying insulation layer and providing connections between the respective electrodes of adjacent electronic parts; and a first surface insulation layer covering the first metal layer and a second surface insulation layer covering the second metal layer.