A nitride group semiconductor light emitting device includes a nitride group semiconductor layer, and an electrode structure. The electrode structure is arranged on or above the semiconductor layer, and includes a plurality of deposited metal layers. The plurality of deposited metal layers of the electrode structure includes first and second metal layers. The first metal layer is arranged on the semiconductor layer side. The second metal layer is arranged on or above the first metal layer. The first metal layer contains Cr, and a first metal material. The first metal material has a reflectivity higher than Cr at the light emission peak wavelength of the light emitting device. According to this construction, the first metal layer can have a higher reflectivity as compared with the case where the first metal layer is only formed of Cr, but can keep tight contact with the semiconductor layer.