A light projecting device of the present invention includes: a light source unit including (i) a laser element for emitting light, (ii) a light converging lens for converging the light emitted from the laser element, and (iii) a light emitting section for emitting light upon receipt of the light converged by the light converging lens; and a reflector for projecting light emitted from the light source unit. The light source unit is provided so as to be attached to or detached from a fixed part to which the light source unit is to be fixed.