To reduce or prevent adhesive particles from being scattered toward a light-emitting portion of an arc tube and an auxiliary reflecting surface of an auxiliary mirror even when an inorganic adhesive injected for fixing the auxiliary mirror to the arc tube is boiled, a method of manufacturing a light source lamp includes: setting a light-reflecting surface of the auxiliary mirror so as to face the light-emitting portion of the arc tube and injecting an adhesive into a gap between the auxiliary mirror and the arc tube; heating and curing the adhesive from a side nearer to the light-emitting portion of the arc tube; and attaching the reflector to the arc tube with the auxiliary mirror fixed thereto. For example, a heated air blowoff and light irradiation toward the adhesive form the side nearer to the light-emitting portion of the arc tube may be performed. Further, a projector includes: an illumination system with the light source lamp; an optical modulator; and a projector lens.