In a semiconductor device of the present invention, a second semiconductor chip is stacked on a first semiconductor chip having a plurality of bonding pads in its central region, with a bonding layer interposed therebetween. A plurality of wires respectively connected to the plurality of bonding pads of the first semiconductor chip are led out to the outside over a peripheral edge of the first semiconductor chip by passing through a space between the first and second semiconductor chips. A retaining member for retaining at least a subset of the plurality of wires is provided in a region on the first semiconductor chip including a middle point between the bonding pads and the peripheral edge of the first semiconductor chip by using a material different from the bonding layer so that the subset of the wires is positioned generally at a center of the spacing between the first semiconductor chip and the second semiconductor chip.