Heat fixing apparatus for sublimating and fixing sublimating ink to recording medium

A heat fixing apparatus has a heating unit for heating a recording medium having a substrate, a fixing layer and a surface layer so as to sublimate sublimating ink applied in advance to the surface layer for transferring the sublimated ink to the fixing layer. The heating unit includes a heating transporting mechanism for transporting the recording medium within a heating space, a heater body for heating air, and a blower mechanism for supplying hot air heated by the heater body to the recording medium being transported by the heating transporting mechanism. The apparatus further includes a flat guide member for coming into contact with the surface of the recording medium being transported by the heating transporting mechanism and a heater for heating the guide member.