PURPOSE: To enable sorting of pieces to be sorted by guiding the pieces to be sorted by forming a concave at a certain angle in the cross section of a conveying path, stably holding the pieces to be sorted in this place by a centrifugal force, thereby preventing the pieces from being intermingled as much as possible.

CONSTITUTION: The pieces 7 such as bottles and cans, which are made of various materials and are to be sorted in a separated form, are transported by the drivable conveying path of a disk-like body 2 having a supply chute 1. This disk-like body 2 has a center region 3 surrounded with a region 4 which is curved upwardly in semi-spherical shape and is downwardly expanded in conical shape, and surrounded with an edge region 5 upwardly expanded in conical shape. The supply chute 1 is slightly inclined and is aligned along the direction tangent to a groove formed by the region 4 and the edge 5 of the disk-like body 2, thereby sliding the pieces 7 from the chute 1 to the groove. The pieces 7 are pressed to the inner flank of the edge 5 by a centrifugal force due to the revolution of the disk-like body 2 during the operation. Thus, the position of the pieces remains unchanged.