A semiconductor device including a base substrate; a semiconductor layer which is disposed on the base substrate and has a 2-Dimensional Electron Gas (2DEG) generated within the semiconductor layer; a plurality of first ohmic electrodes which are disposed on the central region of the semiconductor layer and have island-shaped cross sections; a second ohmic electrode which is disposed on edge regions of the semiconductor layer; and a Schottky electrode part has first bonding portions bonded to the first ohmic electrodes, and a second bonding portion bonded to the semiconductor layer. A depletion region is provided to be spaced apart from the 2DEG when the semiconductor device is driven at an on-voltage and is provided to be expanded to the 2DEG when the semiconductor device is driven at an off-voltage, the depletion region being generated within the semiconductor layer by bonding the semiconductor layer and the second bonding portion.