A sheet processing apparatus (3) includes a pressing lever (46) turnable between a first position where the pressing lever (46) abuts with the sheet bundle on a stacking tray (34) and a second position where the pressing lever (46) is displaced on a side of a discharging part (44) side from the first position. The discharging part (44) has an upper roller (56) and a lower roller (57). The lower roller (57) abuts with a lowermost sheet of the sheet bundle and an upper roller (56) is configured to separate upward from the lower roller (57) during the shifting and to be displaced in a direction approaching the lower roller (57) during the discharging. The pressing lever (46) is configured to project upward from above an apex portion of the lower roller (57) at the second position and to turn into the second position during the shifting.