In a semiconductor light-emitting device, a buffer layer, a un-doped GaN layer, a high carrier concentration n.sup.+-layer, an n-type layer, an emission layer, a p-type layer, and a p-type contact layer are deposited in sequence on a sapphire substrate. The semiconductor light-emitting device includes a light-transparent electrode made of indium tin oxide (ITO) which is deposited in the low pressure vacuum chamber flowing at least oxygen gas through electron beam deposition or ion plating treatment, and a thermal process is carried out.