An image forming apparatus includes: a lower body including a plurality of photosensitive members and having an opening; an upper body which is configured to open and cover the opening; a plurality of exposure units which are supported by the upper body and which are opposed to the photosensitive members when the cover covers the opening; a main substrate provided in the housing; an exposure control substrate which is provided to the upper body and controls light emission of the exposure units; a plurality of first cables which electrically connect the exposure units to the exposure control substrate, respectively, each of the first cables including a plurality of signal lines; and a second cable which electrically connects the exposure control substrate to the main substrate and which includes at least one signal line, a number of which is smaller than a total number of the signal lines included in the first cables.