A semiconductor device of the present invention has a first interconnect layer formed over the semiconductor substrate, and a semiconductor element; the first interconnect layer has an insulating layer, and a first interconnect filled in a surficial portion of the insulating layer; the semiconductor element has a semiconductor layer, a gate insulating film, and a gate electrode; the semiconductor layer is positioned over the first interconnect layer; the gate insulating film is positioned over or below semiconductor layer; and the gate electrode is positioned on the opposite side of the semiconductor layer while placing the gate insulating film in between.