A wavelength conversion device includes a rotating device, a substrate rotated by the rotating device, a wavelength conversion element, and a first cooling device including, on an inside, a space in which working fluid is encapsulated, the first cooling device cooling the wavelength conversion element. The first cooling device is disposed in a position corresponding to the wavelength conversion element. The space extends from an outer edge side of the substrate to a rotation axis side. The first cooling device includes an evaporator and a condenser which are provided in the space. The evaporator includes a liquid retaining part configured to retain the working fluid in a liquid phase. The liquid retaining part is provided at the outer edge side in the space and disposed in the position corresponding to the wavelength conversion element.