A thin film electrode for ohmic contact of a p-type GaN semiconductor includes first and second electrode layers sequentially stacked on a p-type GaN layer. The first electrode layer may include an Ni-based alloy, a Cu-based alloy, a Co-based alloy, or a solid solution capable of forming a p-type thermo-electronic oxide or may include a Ni-oxide doped with at least one selected from Al, Ga, and In. The second electrode layer may include at least one selected from the group consisting of Au, Pd, Pt, Ru, Re, Sc, Mg, Zn, V, Hf, Ta, Rh, Ir, W, Ti, Ag, Cr, Mo, Nb, Ca, Na, Sb, Li, In, Sn, Al, Ni, Cu, and Co. Furthermore, a method of fabricating the thin film electrode is provided.