A fuser includes: a rotating body; a roller configured to convey a sheet in a conveyance direction; a pair of bearings supporting the roller; one side frame made of a resin, supporting one of the pair of bearings; another side frame supporting the other of the pair of bearings, and arranged at a distance from the one side frame in the axial direction; and a center frame made of a metal, including a main-body portion arranged on an opposite side of the rotating body with respect to the roller. One end portion in the axial direction of the main-body portion includes a first fixing portion which is fixed to the one side frame, and a second fixing portion which is arranged on an upstream side of the first fixing portion in the conveyance direction, and is fixed to the one side frame.