A fixing unit for fixing a toner image to a recording medium by passing the recording medium which carries an unfixed image between a pair of rollers which are rotated with being pressed to each other to apply heat and pressure to the recording medium thereby fixing the unfixed image onto the recording medium. The fixing unit includes a housing in which the pair of rollers are provided, the housing having an outer surface; a plate-shaped member for indicating information; and a holding structure for physically holding the plate-shaped member on the outer surface of the housing in a removable manner.