Abstract: The installation comprises a housing (3) which is assigned to one of the walls (5) of the room (42) which is to be lit. A light-guiding arrangement is provided in the housing (3) and is designed such that it can guide light from the outer end part (38) of the housing (3), through an opening (8) in the wall (5) of the room (42) which is to be lit, into said room. The outer mouth opening of the light-guiding arrangement is covered over with the aid of a sheet-like arrangement (25) which is designed such that it allows light to enter into the light-guiding arrangement. An arrangement for ventilating the room which is to be lit is also provided. One of the mouth openings (36) of said ventilating arrangement is located in the covering arrangement (25). A window (1) is arranged in the opening (8) of the room (42) which is to be lit, said window being designed such that it allows not only the incidence of light but also ventilation of the interior (42).