The device of the present invenion includes: a plurality of air generating units containing two adsorbing grooves filling with absorbent, production groove, absorbing valve for closing and opening the flow path to guide material air to the absorbing grooves, exhaust valve, equalizing valve and outlet valve; aggregation production grooves for aggregating production gas storing in each production grooves, which supply constringent material air between two absorbing grooves alternately and implement absorbing motion as well as releasing motion for releasing gas in low pressure. A control device has the function of controlling the running of a plurality of gas generating units and switching running unit number, and controlling so as to offset with same time interval in each unit at the time of switching the motion of each gas generating unit. It is able to answer the accretion of production gas supply flow easily and obtain economical running when decreasing or increasing the production gas supply flow in large range.