According to an embodiment, a semiconductor light emitting device includes a first semiconductor layer, a second semiconductor layer, a dielectric film and an electrode. The first semiconductor layer is capable of emitting light. The second semiconductor layer has a first major surface in contact with the first semiconductor layer and a second major surface opposite to the first major surface, the second major surface including a first region having convex structures and a second region not having the convex structures. The dielectric film is provided at least at a tip portion of the convex structures, and the electrode is provided above the second region.