The invention relates to a semiconductor device. The semiconductor device can be reduced in size. The semiconductor device has a first conductivity type p type well layer extending in the X direction of the main surface of a semiconductor substrate; a reference potential wire coupled with the p type well layer, and extending in the X direction; first and second active regions arranged on the opposite sides of the reference potential wire in the Y direction; and a gate electrode layer extending in the Y direction in such a manner as to cross with the first and second active regions. Then, the gate electrode layer has a first gate electrode of a second conductivity type at the crossing part with the first active region, a second gate electrode of the second conductivity type at the crossing part with the second active region, and a non-doped electrode between the first gate electrode and the second gate electrode.