An image forming apparatus includes a placement tray on which a recording medium is placed and which is attachably and detachably assembled into a housing. The placement tray includes a holding portion having an upwardly concave configuration at one end of the placement tray in an attaching and detaching direction of the placement tray. The holding portion includes at least one air vent for taking air into the housing in a vicinity of at least one of both end portions of the holding portion in a width direction perpendicular to the attaching and detaching direction.