This lighting device has: a light source that outputs excitation light; a wheel that is provided with a wheel substrate, which passes through the excitation light, and a lighting light generating member, which is provided on a first surface of the wheel substrate, and which generates lighting light by means of the excitation light; a light detection unit (24), which is disposed on the side of a second surface of the wheel substrate, said second surface being the surface on the reverse side of the first surface, and which detects the light passed through the wheel; and a control unit (20) that determines, on the basis of the light detected by means of the light detection unit (24), whether a defect or deterioration is generated in the lighting light generating member.