There is disclosed a compound semiconductor light-emitting device of gallium nitride series having high reliability, which can be operated by a low threshold current and a low operation voltage without deterioration. The device comprises a p-type semiconductor structure having high carrier concentration, which can easily form a low resistance p-side electrode, and which can uniformly implant carriers to an active layer highly efficiently. A p electrode contact layer having Mg added thereto is used as a p-type semiconductor layer. At least a Ga.sub.x2 In.sub.y2 Al.sub.z2 N (x2+y2+z2=1, 0.ltoreq.x2, z2.ltoreq.1, 0