An image forming apparatus includes: a main body; an image forming unit including a plurality of photosensitive drums on which electrostatic latent images are formed, respectively; a sheet storing unit detachably attached to the main body and configured to store a recording sheet, and the sheet storing unit being disposed in a first space defined in the main body when the sheet storing unit is attached to the main body; and a belt unit disposed between the plurality of photosensitive drums and the sheet storing unit and including a belt opposing the plurality of photosensitive drums. The belt unit is detachable from the main body through the first space in a state in which at least a part of the sheet storing unit is positioned outside the main body.