PURPOSE: To rationalize copying operation by providing bin members containing copying paper with availability assigning methods that can assign whether corresponding bin members are in use or not.

CONSTITUTION: Copying machine body 1 is fitted with sorter part 2, respective bins of which correspond to distribution-address departments and besides respective bins 21W2n, addresses, e.g. department A for bin 21, department B for bin 22 and so on are written. Operating part 3 over sorter part 2 is provided with assignment buttons 41...4n and corresponding indicating lamps 51...5n and depressing button 42, for example, turns on lamp 52 to assign bin 22 to be used, thereby assigning a document to be distributed to department B. Thus, copied documents from copying machine 1 can immediately be distributed to desired departments. Additionally, assignment buttons 41W45 are reset with reset button 1.