In a fixing device which fixes toner image on a recording material while using a nipping section which is formed between a fixing roller heated by a heating section and a fixing belt which is formed to be endless and rotated by the fixing roller, wherein the fixing device includes a pressing section which presses the fixing belt from an inner surface of the fixing belt against the fixing roller, a sliding member which is mounted between the fixing belt and the pressing section via a lubricant, and a supporting member which supports the inner peripheral surface of an end section of the fixing belt with respect to an axial direction of the fixing belt, wherein a predetermined clearance is provided between the sliding member and the supporting member with respect to the axial direction of the fixing belt.