In various aspects, a semiconductor light emitting device may include a mold resin having a cup shape portion on an upper surface of the mold resin; a first lead provided in the mold resin and extending from the cup shape portion to outside of the mold resin, the first lead having a first lead section and a second lead section, the second lead section of the first lead being thicker than the first lead section of the first lead, the second lead section of the first lead having a hole; a second lead provided in the mold resin and extending from the cup shape portion to outside of the mold resin, having a first lead section and a second lead section, the second lead section of the second lead being thicker than the first lead section of the second lead; a light emitting element mounted on the second section of the first lead in the cup shape portion; a wire electrically connecting the light emitting element and the second lead; and a sealing resin configured to seal the light emitting element and the wire.