An image forming apparatus includes a photosensitive drum, an LED unit, and a housing. The LED unit is configured to expose the photosensitive drum. The LED unit has a light emitting surface. The housing includes a discharge portion and a discharge tray. The discharge portion has a discharge opening configured to discharge a sheet. The sheet discharged from the discharge opening is placed on the discharge tray. The discharge tray has a cleaning opening for cleaning the light emitting surface of the LED unit. The LED unit is configured to move between: a first position at which the LED unit exposes the photosensitive drum; and a second position at which the light emitting surface is closer to the cleaning opening than a state where the LED unit is located at the first position.