An infra-red radiator comprises a ventilated body structure (10) having a cross-web (12) a central leg (14), two side legs (16) and two intermediate support legs (18). Stretched between the legs (14, 16) are two reflectors (24) which are made of a flexible metal foil material and which are located in front of IR-lamps (26). Located between reflectors and body structure are ventilating hollows or cavities (36, 38) and channels (40, 57) for cooling or ventilation air are incorporated in the legs. Inlet channels (40) have upper openings (44) which project cooling air flows along the rearwardly located surface of respective reflectors (24), and lower openings (46) which project cooling air flows (52) along the reflector surface located between the reflector (24) and lamps (26). Turbulent cooling air flows (58) in the hollows (36, 38) behind respective reflectors (24) pass from inlet openings (54) via laterally offset channels (46) in the support legs (18) to outlet channels (57) project in the cooling air, via openings (50), in form of jet or pilot flows (68) which, as a result of an ejector effect, accelerate and amplify the cooling air flows (52).