The method of manufacturing a semiconductor device, including preparing a semiconductor substrate, forming a first insulating layer over said semiconductor substrate, forming first grooves in the first insulating film, forming a gate electrode and a first interconnect in the first grooves, respectively, forming a gate insulating film over the gate electrode, forming a semiconductor layer over the gate insulating, forming a second insulating layer over the semiconductor layer and the first insulating film, forming a via in the second insulating layer, and forming a second interconnect such that the second interconnect is connected to the semiconductor layer through the via. The gate electrode, the first interconnect and the second interconnect are formed by Cu or Cu alloy, respectively.