There are provided a semiconductor device and a semiconductor chip, in which the interconnection is made to be highly reliable by stacking three or more layers of chips without contact therebetween. A semiconductor chip of the present invention comprises a first signal transmission circuit, a silicon substrate on which a first changeover switch is formed, and an interconnection layer on which a first capacitive-coupling upper electrode is formed, wherein a first capacitive-coupling lower electrode is additionally formed on the rear surface of the silicon substrate through a first via hole that penetrates the silicon substrate and, whereas the first capacitive-coupling upper electrode is directly connected to the first signal transmission circuit, the first capacitive-coupling lower electrode is connected to the first signal transmission circuit through the first via hole and through the first changeover switch.