A semiconductor integrated circuit device capable of achieving improvement of I/O processing performance, reduction of power consumption, and reduction of cost is provided. Provided is a semiconductor integrated circuit device including, for example, a plurality of semiconductor chips stacked and mounted, the chips having data transceiving terminals bus-connected via through-vias, and data transmission and reception are performed via the bus with using the lowest source voltage among source voltages of internal core circuits of the chips. In accordance with that, a source voltage terminal of an n-th chip to be at the lowest source voltage is connected with source voltage terminals for data transceiving circuits of the other semiconductor chips via through-vias.