A semiconductor device, which reduces the earth inductance, and a fabrication method for the same is provided.The semiconductor device and the fabrication method for the same including: a gate electrode, a source electrode, and a drain electrode which are placed on a first surface of a semi-insulating substrate 11, and have a plurality of fingers; an earth conductor 26 placed on a second surface of an opposite side with the first surface; a gate terminal electrode 14, a source terminal electrode 18, and a drain terminal electrode 12 which are connecting a plurality of fingers, respectively, and formed for every the gate electrode, the source electrode, and the drain electrode; an active layer formed on the semi-insulating substrate 11 under the gate electrode, the source electrode, and the drain electrode; a multi stage VIA hole composed of a small caliber VIA hole 30 near the first surface and a large caliber VIA hole 20 near the second surface; and an earth electrode 23 which is formed in an internal wall surface of the multi stage VIA hole and the second surface, and is connected from an earth conductor placed at the second surface side for the source terminal electrode 18.