PURPOSE: To increase breakdown strength between a gate and a drain and breakdown strength between the gate and a source and reduce leakage currents, and to lower source resistance, by making the thickness of a contact forming layer have a specific value or above while forming a source metallic electrode and a drain metallic electrode in regions where parts of the contact formation layer are removed through etching.

CONSTITUTION: The thickness 10 of a contact forming layer 5 is brought to 0.3μm or more while a source metallic electrode 8 and a drain metallic electrode 9 are formed into regions shaped by getting rid of part of the thickness 10 of the contact forming layer 5 through etching. Consequently, since the contact forming layer 5 is thickened as 0.3μm, the quantity of side etching is increased when a gate recess region 6 is shaped, and the contact forming layer 5 in high concentration is not brought near to a gate electrode 7 even when the gate electrode 7 is formed subsequently. Accordingly, breakdown strength is improved largely, and leakage currents are reduced. Distances among a two-dimensional electron layer and an active layer and these metallic electrodes are not changed, and source resistance is not increased, and, on the contrary, lowered only by the thickening section of the contact forming layer 5.