It is an object of the present invention to provide a light source apparatus capable of reducing the production cost and increasing productivity. A light source apparatus comprises an approximately spherical discharge container, sealing portions continuously formed from both ends of the discharge container respectively, and a concave reflection mirror disposed so as to surround the discharge lamp, wherein the concave reflection mirror has a spheroidal surface or paraboloid of revolution formed from a front opening edge thereof, a sealing portion receiving section is formed at a head section of the concave reflection mirror and has a flat inner bottom surface, in which an end of one of the sealing portions is received, and an end surface of an end portion of the one of the sealing portions and the inner bottom surface of the sealing portion receiving section are brought into contact.