A luminaire (1) is disclosed, comprising a main reflector (3) with a light emission window (5), and comprising a counter reflector (7) positioned opposite to the main reflector. Means (9) for accommodating at least one electric lamp (11) are provided in the luminaire in between the main reflector and the counter reflector. The counter reflector is provided with a light-transmitting cover (13), acting as an optical waveguide and positioned at a side (15) of the counter reflector facing away from the means (9). The cover is provided with diffusor bodies (21) which scatter the light coupled into the cover and transmitted through the bulk of the cover. Thus a desired distribution and appearance of the optical brightness of the cover is obtained.