The present invention discloses a light device and a fabrication method thereof. An object of the present invention is to provide the light device and the fabrication method thereof an electric/thermal/structural stability is obtained, and a P-type electrode and an N-type electrode can be simultaneously formed. In order to achieve the above object, the inventive light device includes: a GaN-based layer; a high concentration GaN-based layer formed on the GaN-based layer; a first metal-Ga compound layer formed on the high concentration GaN-based layer; a first metal layer formed on the first metal-Ga compound layer; a third metal-Al compound layer formed on the first metal layer; and a conductive oxidation preventive layer formed on the third metal-Al compound layer.