To provide a projector including a light source device which can simply adjust light amount balance of fluorescent light and diffusion light.

The light source device includes: a blue laser light emitting element which emits light of a predetermined wavelength bandwidth; a light emitting wheel 101 on which a fluorescent light emitting region 103 having a green phosphor layer 105 laid thereon and a diffusion region 104 having a diffuser 106 attached thereto are provided next to each other in a circumferential direction, and on which the green phosphor layer 105 or the diffuser 106 is provide so as to be positioned on an optical axis of the blue laser light emitting element; a wheel motor which causes the light emitting wheel 101 to rotate; and a movement mechanism which enables the light emitting wheel 101 to move together with the wheel motor in a radial direction thereof. Between the fluorescent light emitting region 103 and the diffusion region 104 are positioned two boundary lines a, b, at least one of which does not coincide with the radius. In other words, the fluorescent light emitting region 103 and the diffusion region 104 are formed such that the ratio of the lengths of arcs of concentric circles centered on the center of the light emitting wheel 101 varies according to a distance from the center of the light emitting wheel 101.