According to one embodiment, a method for manufacturing a semiconductor light emitting device includes forming a separation groove on a major surface of a substrate. A semiconductor layer including a light emitting layer is formed on the substrate. The separation groove separates the semiconductor layer into a plurality of elements. The method includes forming an insulating film on the major surface of the substrate. The insulating film covers the semiconductor layer and a bottom surface of the separation groove provided on the substrate. The method includes separating the substrate from the semiconductor layer by irradiating the semiconductor layer with laser light from an surface of the substrate opposite to the major surface. An edge portion of irradiation area of the laser light is positioned near an edge portion of the semiconductor layer neighboring the separation groove.