Sheet sorting device and image forming apparatus

An image forming apparatus comprising:

• an image forming unit configured to form an image on a sheet;
• three or more trays including a predetermined tray detachable from an apparatus main body and a tray different from the predetermined tray;
• a discharge unit configured to discharge a sheet on which an image is formed by the image forming unit, to any one of the three or more trays;
• a control unit configured to set a sheet discharge destination such that a sheet conforming to a preset condition is discharged to the predetermined tray through the discharge unit;
• and
• a tray detection unit configured to detect that the predetermined tray is detached from the apparatus main body,
• wherein, in a case where the tray detection unit detects that the predetermined tray is detached from the apparatus main body, the control unit sets a sheet discharge destination that has been set to the predetermined tray to the tray different from the predetermined tray based on a state of each of the trays other than the detached predetermined tray.