A semiconductor device includes an active region famed in a semiconductor layer formed on an insulating film famed in a semiconductor substrate and having a first extension portion extending in a first direction and a second extension portion extending in a second direction intersecting with the first direction, a first diffusion layer electrode of a first conductivity type provided in the first extension portion, second and third diffusion layer electrodes of a second conductivity type provided in the second extension portion so as to interpose a first connecting portion connecting the first extension portion and the second extension portion, a first gate electrode famed on the first extension portion between the first diffusion layer electrode and the first connecting portion through an insulating film famed on the semiconductor layer, and a second gate electrode famed on the first connecting portion through the insulating film famed on the semiconductor layer.