PURPOSE: To obtain an image forming apparatus equipped with a copy post- processing device having a structure capable of performing a plurality of the processings to transfer paper after copying at the same place.

CONSTITUTION: In an image forming apparatus equipped with a copy poss- processing device 15 bringing both ends of a bin 4 forming a delivery tray in the lateral direction of transfer paper into engagement with the groove parts of a freely rotatable helical screw 6 and a helical cam 7 and performing the sorting and distribution of the delivered transfer paper by the rising and falling operation of the bin 4, a pair of guide shafts 16 provided in opposed relation to the leading end in the delivery direction of the transfer paper delivered to the bin 4 so that the axial direction thereof is set along the direction of the transfer paper and a plurality of the post-processing units 18, 19 supported on the guide shafts 16 in a freely shakable manner in opposed relation to the leading end in the delivery direction of the transfer paper are mounted on the copy post-processing device 15.