Organic electroluminsecent light source device

Provided is an organic electroluminescent light source device which sequentially comprises a transparent electrode layer, a light emitting layer, a reflective electrode layer and a reflective layer in this order from the light emission surface side, and which is characterized in that the reflective electrode layer has a through hole and the reflectance of the reflective layer is higher than the reflectance of the light emitting layer-side surface of the reflective electrode layer. Particularly provided is a light source device which additionally comprises a diffusion element for diffusing light.