An element using a semiconductor layer is formed between wiring layers and, at the same time, a gate electrode is formed using a conductive material other than a material for wirings. A first wiring is embedded in a surface of a first wiring layer. A gate electrode is formed over the first wiring. The gate electrode is coupled to the first wiring. The gate electrode is formed by a process different from a process for the first wiring. Therefore, the gate electrode can be formed using a material other than a material for the first wiring. Further, a gate insulating film and a semiconductor layer are formed over the gate electrode.