PURPOSE: To eliminate operator's manual operation and to minimize a waste of forms by switching a gate when a jam occurs in a sorter and storing temporarily a discharged form in a tray exclusive for jamming.

CONSTITUTION: A guide member 4 is provided with the gate which is switched through jam detecting sensors 11 and 12, and when no jam occurs, the gate is positioned over the guide member 4 at a distance to send a discharged form to a conveying member 5 through the guide member 4. The gate 13 contacts the guide part 4 to send the discharged form in the tray 10 only for jamming through the guide member 14. An operator after removing a jamming form in the sorter 3 drives a sending-out member 9 to store forms stacked in the tray 10 only for jamming on a rack 8 through a form distributing member 7.