US Patent 10991606 Purge stocker

A purge stocker has a plurality of shelf zones each including a plurality of purge shelves each configured to purge inside of a storage container placed thereon with purge gas. The purge stocker includes: a flow-rate adjusting unit configured to adjust the flow rate of purge gas supplied to the purge shelves for each shelf zone; a conveying device configured to convey the storage container; and a control unit configured to control conveyance of the storage container by the conveying device. When the number of scattered empty shelves is equal to or larger than a predetermined shelf count that is the number of the purge shelves included in each shelf zone, the control unit performs shelf-changing control of causing the conveying device to transfer the storage container such that an empty shelf zone in which all of the purge shelves included therein are empty is newly formed.