Fixing apparatus providing a fixing apparatus capable of suppressing a temperature rise in a non-sheet-passing portion without degrading first print out time

A fixing apparatus for fixing a toner image formed on a recording material to the recording material, the fixing apparatus comprising:

• a rotatable cylindrical film;
• a heater including a substrate made of a ceramic material, a heat generating resistor formed on the substrate, and a glass coat layer covering the heat generating resistor, the heater having a first surface which is a surface of the glass coat layer in contact with an inner peripheral surface of the film and a second surface disposed on an opposite side of the first surface;
• a support member configured to support the heater;
• a pressure member configured to form a nip with the heater through the film to heat the toner image and fix the toner image onto the recording material at the nip;
• a thermal conductive member having a thermal conductivity higher than the thermal conductivity of the substrate, the thermal conductive member being disposed above the second surface;
• and
• a thermal-resistant member disposed between the thermal conductive member and the substrate, a thermal resistance in a thickness direction of the thermal-resistant member being higher than the thermal resistance in the thickness direction of the thermal conductive member.