In a high frequency amplifying MOSFET having a drain offset region, the size is reduced and the on-resistance is decreased by providing conductor plugs 13 (P1) for leading out electrodes on a source region 10, a drain region 9 and leach-through layers 3 (4), to which a first layer wirings 11a, 11d (M1) are connected and, further, backing second layer wirings 12a to 12d are connected on the conductor plugs 13 (P1) to the first layer wirings 11s, 11d (M1).