An image forming apparatus includes: an image forming unit having a plurality of photoconductor drums arranged in tandem; an intermediate transfer belt arranged opposite to the photoconductor drums and configured to receive developer images formed on the photoconductor drums and to transfer the developer images onto a recording sheet; a cleaning unit comprising a cleaning member positioned in contact with the intermediate transfer belt and configured to collect substance adhering to the intermediate transfer belt, and a receptacle configured to store the substance collected by the cleaning member, wherein the cleaning unit is arranged on the same side as the image forming unit with respect to the intermediate transfer belt; and a support member configured to support the image forming unit and the cleaning unit and to be pulled out from a main body.