A semiconductor device, includes a semiconductor substrate, a first interconnect layer formed over the semiconductor substrate, a gate electrode formed in the first interconnect layer, a gate insulating film formed over the gate electrode, a second interconnect layer formed over the gate insulating film, an oxide semiconductor layer formed in the second interconnect layer, and a via formed in the second interconnect layer and connected to the oxide semiconductor layer. The gate electrode, the gate insulating film and the oxide semiconductor layer overlap in a plan view.