A fixing apparatus fixes an image formed on a recording material and includes a guiding member for guiding movement of the recording material, provided in a recording material passing opening of the apparatus, a rib projecting from a recording-material passing surface of the guiding member, for being contacted by the recording material, a shutter provided at a position opposing the guiding member and movable between a position for opening the passing opening and a position closing the passing opening, and a projection provided at a position of the shutter opposing a portion of the guiding member not having the rib with respect to a direction perpendicular to a recording material feeding direction. When the shutter takes the closing position, the clearance between the rib and the shutter is larger than the clearance between the guiding member and the projection.