A light shielding member formed of an annular metal base material includes a front surface, a rear surface facing away from the front surface, and an outer peripheral surface connecting the front and rear surfaces in an outer periphery of the light shielding member. The outer peripheral surface includes a ridge that is protruded outward furthest therein in a radial direction of the light shielding member, in a cross section that is parallel to a plane perpendicular to the front surface.