An apparatus for fixing toner images in which a radiating member is interposed between a near infrared red ray source and a path of movement of a support sheet bearing a toner image for producing far infrared rays. The radiating member is constructed with metal foils such that the foils form a large number of complicated paths for the near infrared rays from said source so that the rays are converted into heat after infinite repeated reflection. Air is sprayed through the complicated paths toward the sheet path to improve the fixing efficiency by an atmospheric heating in addition to the far infrared heating and further to prevent a combustion of the sheet in the event it is jammed.