The semiconductor device

A semiconductor device comprising: forming a first nitride semiconductor layer (13), and a band gap larger than the second nitride semiconductor layer of the first nitride semiconductor layer (13) (14); a second penetrating nitride the semiconductor layer (14) and the removed portion of the first recess portion nitride semiconductor layer (13); and an electrode buried in the recess portion (17). A two-dimensional electron gas layer (13a) immediately below the first nitride semiconductor layer (13) interface with the second nitride semiconductor layer (14) is. Electrode (17) and the second nitride semiconductor layer (14) at a first contact surface (16a) in contact. Portion of the electrode (17) and the two-dimensional electron gas layer (13a) of the second contact surface (16b) connected to the first contact surface (16a) below the contact. A first contact surface (16a) is the width of the recess widens from bottom to top shape. At the junction, the second contact surface (16b) inclined with respect to the upper surface of the first nitride semiconductor layer (13) is steeper than the first contact surface (16a).