To easily perform the treatment of a jam generated within a sorter body, failure repairing, or maintenance inspection by opening all sheet carrying passages of transfer material between rollers.

In a jam treatment when a carrying sheet is supposed to be clogged in a lid body part, the hook 7b of a lid body 4 is removed from the fixture 8b of a moving frame 2 to open the lid body 4 around a rotating fulcrum 5. When the carrying sheet is supposed to be clogged in the part of the moving frame 2, the hook 7a of a fixed frame 1 is removed from the fixture 8a of the moving frame 2 to move the moving frame 2 in the direction separating from the fixed frame 1. Further, when the jam position is not found, both vertical and horizontal sheet carrying passages 21, 22 are opened to treat the jam. Thus, jam treatment, inspection maintenance, or the like can be facilitated, and the practical availability is enhanced.