A semiconductor device 10 according to the present invention includes an active layer 14 supported on a substrate 11 and having two channel regions 14c1, 14c2, a source region 14s, a drain region 14d, and an intermediate region 14m formed between the two channel regions 14c1, 14c2; a contact layer 16 having a source contact region 16s, a drain contact region 16d, and an intermediate contact region 16m; a source electrode 18s; a drain electrode 18d; an intermediate electrode 18m; and a gate electrode 12 facing the two channel regions and the intermediate region through a gate insulating film 13 interposed therebetween. An entire portion of the intermediate electrode 18m that is located between the first channel region 14c1 and the second channel region 14c2 overlaps the gate electrode 12 through the intermediate region 14m and the gate insulating film 13.