A light emitting device, has: a light emitting element; a substrate having a first main surface on which the light emitting element is mounted, and recesses on side surfaces adjacent to the first main surface, a cap covering the light emitting element, and having a light-transmissive member and a metal frame that supports the light-transmissive member and has side pieces extending toward the substrate from above the first main surface of the substrate, and tabs that is bended and extend from the side pieces and housed a part thereof in the recesses of the substrate.