Air taken in from the paper exit fan at the front is discharged from the fusing fan at the rear to outside the machine. By cooling the paper immediately after fusing, it is used for not only cooling of the paper exit sensor but also reduction of stored heat of stack paper and reduction of curl are realized. This also serves to prevent dew condensation of the paper discharge guide sheet. As a measure against odor, an odor filter is installed downstream from the fusing fan.