PURPOSE: To make it possible to prevent workpieces which are chained in a ring-like shape, from being scratched due to collision one another, by laying a support member for annularly supporting the workpieces chained in the ring- like shape in a barrel tank, in parallel with the rotary shaft of the barrel tank.

CONSTITUTION: One or more cylinders 3 are secured to the center section of the bottom plate 2 of a barrel tank 1 having a hexagonal cylindrical surface in parallel with the side wall of the barrel tank 1, and a plurality of through- holes 4 for passing an abrasive agent therethrough are formed in each cylinder 3 in a symmetrical pattern having three vertical rows and two transverse rows. Further, workpieces 11 chained in a ring-like shape are supported annularly by the cylinders 3 in order to be subjected to barrel polish. Thus, each workpiece to be polished makes into contact with the abrasive agent over the entire surface thereof so that it is fluidly polished without being damaged due to collision one another. Further, there is no risk of blocking holes in the workpiece with abrasion chips, and further there is required no troublesome thread insertion. Therefore, the workpieces may be delivered as it is, as articles, and a predetermined number of them may be handled in one time and be delivered as it is.