Image fixing apparatus for fixing a toner image through a nip, the apparatus including a cylindrical film; a nip forming member contacting an inner surface of the film; a pressing rotatable member forming the nip in cooperation with the nip forming member with the film interposed therebetween; and a regulating member for regulating movement of the film in a direction of a generatrix of the film, wherein the regulating member has an opposing surface opposing an edge of an end portion of the film with respect to the direction of the generatrix, and the opposing surface has a regulation region for regulating the edge of the film when the film is driven and moves in the generatrix direction, wherein the regulation region is narrower in a downstream side of a center portion of the nip than in an upstream side thereof with respect to a sheet feeding direction.