In a laser printer apparatus, a top cover is arranged to cover a base member, a fixing unit, and a laser scanning unit. At a raised portion formed for reinforcement at an end portion of the base member on the side of fixing unit, a plurality of openings are formed along one direction, with the area of the openings made gradually larger as the distance from a fan increases. On the top cover, a wall portion is formed integrally, protruding to the side of the base member, and by the wall portion and the raised portion, an air passage is formed. Thus, a laser printer is provided in which the fixing unit and the laser scanning unit can be cooled, without necessitating any additional member.