Gas separation method and apparatus

A gas separation apparatus comprising:

• a selective permeable membrane provided with a separation-functional layer that is selectively permeable to a gas to be separated, and
• a first treatment chamber and a second treatment chamber separated by the selective permeable membrane, wherein
• the gas separation apparatus is configured to supply a mixed gas containing the gas to be separated to the first treatment chamber or to generate the mixed gas in the first treatment chamber, and to separate the gas to be separated from the mixed gas by having the gas to be separated permeate from a first treatment chamber side of the selective permeable membrane to a second treatment chamber side of the selective permeable membrane,
• the selective permeable membrane has a laminated structure in which a hydrophilic porous membrane, the separation-functional layer supported by the hydrophilic porous membrane, and a first protective membrane of a hydrophobic porous membrane laminated on the separation-functional layer are stacked in order,
• the separation-functional layer includes a gel layer of a hydrophilic polymer containing water, and
• the first treatment chamber is provided on a hydrophilic porous membrane side with respect to the separation-functional layer of the selective permeable membrane, and the second treatment chamber is provided on a first protective membrane side with respect to the separation-functional layer of the selective permeable membrane.