Abstract: The invention relates to a sorter of the type in which a distributor moves relative to a plurality of bins arranged fixedly along the inlets of bins to thereby distribute sheets into the bins individually, and is constituted by a pair of belts for transporting the sheet received from the copying machine toward the distributor and a tensioner for tensing the belts. Another arrangement of the invention has a device for preventing the movement of the distributor in both forward and reverse direction while the distributor is at a stop. Further another arrangement of the sorter includes structure for successfully guiding the leading edge of the sheet into a pair of rollers provided the distributor.