A lamp can include LED lamps as a light source. An optical guide path including a first reflecting surface and a second reflecting surface can be provided between the LED lamp and a lens that radiates an illumination light. The optical guide path can be integrally composed of a high-refractivity material. Thus, the light passing through the optical guide path can more efficiently reach the lens. In addition, the integral optical guide path requires less assembly and thus can improve accuracy of assembly and can possibly result in a large gain in the amount of light emitted from the lamp.