An image heating apparatus includes a flexible sleeve, a sliding member for sliding on the inner periphery of the sleeve, and a back-up member for forming a nip portion together with the sliding member through the sleeve. A recording material for bearing an image is heated while being held and conveyed by the nip portion, and a regulation member is set by facing the edge surface of the sleeve in the generatrix direction to regulate the movement of the sleeve in the generatrix direction, the regulation member having a regulation surface with which the edge surface of the sleeve contacts when the sleeve moves in the generatrix direction. The regulation surface of the regulation member has a curved-surface area in which a line when the regulation surface is cut at a virtual plane almost parallel with the nip portion is a curved line expanded toward the edge surface of the sleeve. Thereby, an image heating apparatus is provided which is able to restrain deterioration of the durability of the flexible sleeve.