An image heating apparatus is provided for heating an image formed on a recording material having a resin material layer at an image formation side thereof. The apparatus includes a belt for closely contacting and heating an image on the recording material to provide a high glossiness image, and a cooler for cooling the recording material heated by the belt. The belt comprises a layer of siloxane-modified polyimide and has a thermal expansion coefficient of not less than 6.times.10.sup.-5/.degree. C. and not more than 10.times.10.sup.-5/.degree. C.