A semiconductor light emitting device according to an embodiment includes: a substrate; an n-type semiconductor layer formed on the substrate; an active layer formed on a first region of the n-type semiconductor layer, and emitting light; a p-type semiconductor layer formed on the active layer; a p-electrode formed on the p-type semiconductor layer, and including a first conductive oxide layer having an oxygen content lower than 40 atomic %; and an n-electrode formed on a second region of the n-type semiconductor layer.