The present invention provides a semiconductor device having a low-k film including an interconnect layer and a highly-reliable through-substrate contact plug. The semiconductor device includes: a semiconductor substrate having a first surface and a second surface facing each other; a first insulating film formed on the first surface of the semiconductor substrate and having a specific permittivity of 4 or higher; a circuit constituent element formed on the first surface of the semiconductor substrate and covered with the first insulating film); a contact plug formed in the first insulating film and electrically connected to the circuit constituent element; a through-substrate contact plug penetrating through the semiconductor substrate and the first insulating film; a second insulating film formed on the first insulating film and having a specific permittivity of 3.5 or lower; an interconnect layer formed in the second insulating film and electrically connected to the through-substrate contact plug and the contact plug; a first electrode formed in an exposed state and external to the second insulating film and electrically connected to the interconnect layer; and a second electrode formed in an exposed state and external to the second surface of the semiconductor substrate and electrically connected to the through-substrate contact plug.