There is provided a semiconductor light emitting device that can easily dissipate heat, improve current spreading efficiency, and reduce defects by blocking dislocations occurring when a semiconductor layer is grown to thereby increase reliability. A semiconductor light emitting device including a substrate, a light emitting structure having an n-type semiconductor layer, an active layer, and a p-type semiconductor layer sequentially laminated, and an n-type electrode and a p-type electrode formed on the n-type semiconductor layer and the p-type semiconductor layer, respectively, according to an aspect of the invention may include: a metal layer formed in the n-type semiconductor layer and contacting the n-type electrode.