The invention relates to a high-quality semiconductor light emitting device which suppresses current concentration. The semiconductor light emitting device includes an n-type semiconductor layer, an active layer and a p-type semiconductor layer sequentially formed on a substrate. The semiconductor light emitting device further includes a p-electrode formed on the p-type semiconductor layer and an n-electrode formed on a surface of a mesa-etched portion of the n-type semiconductor layer. A trench is formed in the n-type semiconductor layer to prevent current concentration. The trench is extended from an upper surface of the mesa-etched portion of the n-type semiconductor layer or from a bottom surface of the substrate into the n-type semiconductor layer at a predetermined depth.