In an image forming apparatus, a plurality of process units each including a photoconductor drum are arranged in tandem; a plurality of exposure units configured to expose the photoconductor drum to light to form an electrostatic latent image thereon are each disposed above and opposite to the corresponding photoconductor drum; an output tray configured to receive an ejected recording sheet on which an image has been formed is disposed above the plurality of exposure units; and an image reader unit configured to read an image of a source document is disposed above the output tray with a predetermined space provided between the image reader unit and the output tray. At least one of the exposure units and at least a part of the output tray are movable together into the predetermined space, whereby the plurality of process units are allowed to be pulled out in a direction of tandem arrangement thereof.