Provided are a nitride semiconductor field effect transistor (FET) and a method of fabricating the nitride semiconductor FET. The nitride semiconductor FET includes a first semiconductor layer, a second semiconductor layer, a two-dimensional electron gas layer, a T-shaped gate, and a source/drain ohmic electrode. The first semiconductor layer is formed on a substrate. The second semiconductor layer is formed on the first semiconductor layer and has a bandgap energy that is different from the bandgap energy of the first semiconductor layer. The two-dimensional electron gas layer is formed of a hetero-junction of the first semiconductor layer and the second semiconductor layer in an interfacial area between the first semiconductor layer and the second semiconductor layer. The T-shaped gate is formed on the second semiconductor layer and is connected to the second semiconductor layer. The source/drain ohmic electrode is formed by sequentially forming an Ni (or Cr) layer, an In layer, an Mo (or W) layer, and an Au layer at both sides of the second semiconductor layer and on the first semiconductor layer.