A projector is provided which can secure long-term reliability and enable high-speed start-up through suppression of local heat generation of phosphor. The projector includes a light source device including an excitation light source emitting excitation light, a phosphor disk on which a phosphor that converts the excitation light into fluorescence is continuously formed in a circumferential direction of the phosphor disk, a motor unit rotating the phosphor disk in the circumferential direction, a light modulation device generating an image light through modulation of light including the fluorescence, and a projection optical system projecting the image light. If the number of rotations of the phosphor disk reaches a predetermined number that is smaller than a target number, the excitation light source is turned on, while if the number of rotations of the phosphor disk is increased after reaching the predetermined number, an output of the excitation light source is increased.