To provide a paper discharge mechanism capable of providing a high working efficiency by reducing a user waiting time, discharging a large volume of paper, and minimizing the height thereof.

This paper discharge mechanism comprises a first discharge port 31 for discharging paper to a large capacity stack tray 33 and a second discharge port 32 for discharging paper to a plurality of mail boxes 34. The large capacity of stack tray 33 is installed above the plurality of mail boxes 34. In addition, the plurality of mail boxes 34 is controllably moved by a control part 100 in conjunction with the vertical movement of the large capacity stack tray 33.