To provide an illuminating device-cum-air cleaning device that solves a heat problem and allows efficient operation of an air cleaning means.Air inlets/outlets 3A and 3B are provided in a wall surface of a housing 10 to which an illumination light source 2 is attached. A fan 4 is provided in the housing 10 to generate a forced air flow inside and outside the housing 10 through the air inlets/outlets 3A and 3B and discharge heat from the illumination light source 2 by the forced air flow to the outside of the housing 10. In the middle of a flow path for the forced air flow a within the housing 10, a photocatalyst 50 facing the flow path and a UV light source 51 irradiating the photocatalyst 50 with light including ultraviolet rays are provided as air cleaning means 5.
