A light-emitting device, comprising: a substrate; a semiconductor stacking layer comprising a first type semiconductor layer on the substrate, an active layer on the first semiconductor layer, and a second semiconductor layer on the active layer; and an electrode structure on the second semiconductor layer, wherein the electrode structure comprises a bonding layer, a conductive layer, and a first barrier layer between the bonding layer and the conductive layer; wherein the conductive layer has higher standard oxidation potential than that of the bonding layer.