To effectively use the upper part of a roller conveyor 20 for warehousing as a temporary stocking (buffer stock) space for a commodity W.

When the commodity W is conveyed onto the roller conveyor 20 for warehousing, the commodity W is conveyed towards a warehousing station 28. When the commodity W is not (or cannot be) immediately stored in the commodity storing rack 3 by a stacker crane 13, the commodity W is positioned on a predetermined pair of commodity supporting bars 34 (positioned below a commodity conveying side 26), the drive of the roller conveyor 20 for warehousing is temporarily stopped, the commodity supporting bars are raised, and the commodity W is lifted by the commodity supporting bars 34.