PURPOSE: To perform the high-speed accumulation treatment of articles without stopping article supply to an accumulation conveyer.

CONSTITUTION: Articles are supplied successively to the accumulation part of an accumulation conveyer 18 via a carrying conveyer 16. In the case where article supply timing from the accumulation conveyer 18 to a transfer conveyer is not attained when the given number of articles are accumulated at an accumulation part, the downstream end part of the carrying conveyer 16 is risen. In the case where article supply timing is attained when the given number of articles are not accumulated at the accumulation part, the accumulation part of the accumulation conveyer 18 is lowered, and also the carrying conveyer 16 is lowered so as to follow the movement of the accumulation part. Moreover when article supply timing is attained concurrent with accumulating the given number of articles at the accumulation part, the accumulation part of the accumulation conveyer 18 is lowered, and also the carrying conveyer 16 is elevated.