A surface emission apparatus includes a first light source for emitting invisible light rays; a second light source for emitting visible light rays; a light guide having a light entrance surface for entering therethrough into the light guide the invisible light rays emitted from the first light source and the visible light rays emitted from the second light source, and a light exit surface for emitting the invisible light rays and the visible light rays therethrough out of the light guide; and a plurality of optical devices disposed on a surface of the light guide which confronts the light exit surface, for scattering more of the invisible light rays than the visible light rays.