PURPOSE: To prevent the occurrence of fusion, coagulation, etc., of toner in a cleaning machine and a developing device by providing a ventilation opening on the bottom of an outer cover, ventilation openings on the side plates of the outer cover, and fans on said ventilating openings.

CONSTITUTION: A sheet material feeding device 2 is disposed slantly above and behind an image forming and processing device 2; a fixing device 14 fixing an unfixed image formed on sheet material, and a fixed sheet material ejecting device 40 are disposed slantly below and in front of the device 2; and an ejected paper tray is disposed on the front side of the device 2. In this case, the ventilation opening 22 is provided on the bottom 1a of the outer cover right under and in the vicinity of the process cartridge 2, the ventilation openings 26 and 27 are provided on the side plates 1b of the outer cover, in the vicinity of the position corresponding to the edge of the fixing device in the longitudinal direction of the fixing device, and one or more fans 23 are provided on a part or all of the ventilation openings. Thereby, the occurrence of fusion, coagulation, etc., of toner in a cleaning machine and a developing device can be prevented.