A light emitting device includes a semiconductor multilayer structure having a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and an active layer. A reflecting layer is provided at a side of one surface of the semiconductor multilayer structure and reflects a light emitted from the active layer. A supporting substrate of Si or Ge is provided at an opposite side of the reflecting layer with respect to the side of the semiconductor multilayer structure and supports the semiconductor multilayer structure via a metal bonding layer. A back surface electrode is provided at an opposite side of the supporting substrate with respect to a side of the metal bonding layer and includes Au alloyed with the support substrate. A hardness of the back surface electrode is higher than a hardness of the Au.