PURPOSE: To ensure thick paper sheets delivered from an image formation device to be stacked in a sorter device.

CONSTITUTION: A sorter device 10 is provided with the first carrying passage 5 comprising an inlet feed roller pair 12 for carrying general recording paper sheets, feed rollers 4 laid at the upper section of the device 10 and the first guide plate 4A. Also, the device 10 is provided with the second carrying passage 6 for carrying thick paper sheets 18, comprising inlet feed rollers 12 laid in an approximately horizontal direction from the delivery port 1a of an image formation device 1, and the second guide plate 7. In addition, a selector guide 3 is provided at a position where the first and second carrying passages 5 and 6 are branched. This guide 3 is selectively operated for carrying the general recording paper sheets via the first carrying passage 5, and the thick paper sheets 18 or the like via the second carrying passage 6.