An exhaust mechanism for use in an image development apparatus exhausts air from within the apparatus, taking advantage of an air flow generated by the heating of a fixing unit without the need for an air blower. The apparatus includes a transport path for allowing a recording medium, to which a toner image formed on a photoconductive body, is transferred, to pass therethrough, a transfer unit disposed below the photoconductive body for transferring the toner image to the recording medium, the fixing unit having a heater, and a partitioning plate which separates a space formed below the transfer unit from a space that accommodates the photoconductive body, a toner image forming unit, and the fixing unit, and which is provided with an opening for permitting air to flow near the transfer unit. With this arrangement, a ventilation path for exhausting air outwardly from within the apparatus is formed without the need for the air blower, in which a rising air flow is exhausted, passing through the opening in the partitioning plate, near the transfer unit, and through an opening formed in the cabinet of the body of the apparatus.