Abstract: According to one embodiment, a light source is mounted on one side of a base body, a cap is mounted on the other side of the base body and a lighting circuit is mounted in the cap. In the cap, a circumferential portion is formed, and a projection portion being projected from the other side of the circumferential portion and having an inner space opened to the one side is formed. The lighting circuit has a substrate and a plurality of components mounted on the substrate. The components include a first component group mounted on a center portion of the substrate and having a height stored in the projection portion and a second component group mounted on a peripheral portion of the substrate and having a smaller height stored in the circumferential portion.