Provided is a projector light source which can effectively project a light beam having a sufficient volume from a lamp as a light source, and which is highly accurate and is excellent in workability. The projector light source comprising an arc tube for emitting a light beam; and a concave reflector including a hold part for holding the arc tube, and having a concave reflection surface for reflecting the light beam from the arc tube so that the light beam outgoes through an opening of the reflector, the concave reflector comprising a first reflector located in the vicinity of the hold part for holding the light emitting tube, and second reflector located in a part other than the hold part, and made of a material different from that of the first reflector. Further, the first reflector is made of heat-resistant glass, and the second reflector is made a material containing a heat-resistant organic material having a thermal deformation temperature which is lower than that of the heat-resistant glass.