A fuser includes a cylindrical heating rotating body including a heat generator and a pressure rotating body including a circumferential face which has contact with the heating rotating body to form a nip portion for fusing, wherein a disk-like outside plate, which is exposed outside, is provided in one end or both ends of the heating rotating body in a rotation axis direction, a disk-like inside plate is provided in an inner circumferential face of the heating rotating body on an inside of the outside plate to have an interval relative to the outside plate, a center vent is provided near a center of the outside plate, an outer edge vent is provided in an outer edge or the neighborhood thereof of the outside plate, and a flow path, which connects the center vent and the outer edge vent, is provided between the outside vent and the inside vent.