There is provided an image forming apparatus including a casing which includes one side wall extending in a vertical direction and has a first opening; and a discharge portion which receives a recording medium having a developer image formed thereon, and a cassette which accommodates recording media and is removably mounted to the casing. The casing further includes a tray which is disposed near the one side wall and receives a recording medium to be transported into the casing through the first opening. The tray is rotatable between a first position where the tray is bent so as to cover at least part of the one side wall and the discharge portion and a second position where the tray extends so as to be separated from the one side wall and receives a recording medium to be supplied into the casing through the first opening.