PURPOSE: To make work throwing operations into automation, by installing an aligning conveyor and a transfer direction adjuster in position between a throwing conveyor and a multistage weight selector, while feeding each work in a direction congruent with a belt transfer direction of the said selector and at a synchronous speed.

CONSTITUTION: Each of works 3 such as fishes and the like are first transferred in an A direction by a throwing conveyor 1 and fed to a throwing part 5 of an aligning conveyor 4. Next, these works 3 are mounted one by one on a space 8 partitioned off by a partition plate projection 6 and transferred in a B direction by an endless belt 7. In succession, each work 3 is made to drop from a discharge part 11 after being guided by a guide plate 10, and fed to a throwing port 13 of a transfer direction adjuster 12. The dropped work 3 is housed in a space 17 partitioned off by a partition plate 14 and fed to a multistage weight selector 20 after being guided by a guide plate 16. And, the work 3 is received by any of plural mounting blocks 23 and transferred in a D direction, while they are selected by weight, then discharged to each of belts 26aW26e of a discharge conveyor 25.