Provided is an image forming apparatus that cools a cooled unit with high cooling efficiency in the longitudinal direction with a simple structure. A connecting opening portion is provided in a boundary surface that partitions between a cooling duct and a parallel duct. A rectifying plate is shaped so as to deflect a flow of air from the right side to the left side in the vicinity of the connecting opening portion toward the lower side or toward the upper side. Low-temperature cooling air flow from the parallel duct into the cooling duct via the connecting opening portion. Alternatively, inside the cooling duct, high-temperature cooling air is removed through the connecting opening portion.