PURPOSE: To temporarily collect product groups to obtain necessary package units continuously by circularly conveying an arbitrary amount of part less than a package unit and by executing combinational arithmetic operation.

CONSTITUTION: The upstream terminal of a circular conveyor 2 with continuously installed part pans 3 is equipped with a part chuter 5 that is used to chute a number of parts 4 less than a collecting quantity. Further, at a lower section of the circular conveyor 2, a collector unit 14 that receives parts 4 discharge from the part pans 3 and that temporarily collects an amount of part group as collecting unit. In this parts container 14, in order to chute a part group into part cases 12 in synchronous with traveling of the part cases 12 of part conveyor 11, the bottom section consists of hoppers 15 and 16 that can be freely opened and closed, and a chute 17. Furthermore, an arithmetic unit 19, while conveying parts 4 on the circular conveyor 2, combines part groups put on two sets of part pans 3 to obtain some amount of parts as a collecting unit. Thus, parts 4 are collected during conveying, thereby being able to collect parts temporarily and to obtain a necessary package unit.