US Patent 10923372 Gas injection device

There is provided a gas injection device configured to prevent entry of atmospheric air when charging gas into a FOUP. In order to realize such a gas injection device, the gas injection device is structured so as to include: a gas supply port 72 through which inert gas is supplied; a nozzle main body 71 including a gas passage 77 communicating with the gas supply port 72; an opening/closing mechanism 92 configured to close the gas supply port 72; and an opener 96 configured to cause the opening/closing mechanism 92 to open the gas supply port 72 closed by the opening/closing mechanism 92.