Abstract: An adsorbing element for adsorbing and releasing a gas includes a plurality of adsorbing sheets. Each adsorbing sheet includes gas-permeable sheets such as non-woven fabrics or filter papers, and an adsorbing material filled between the gas-permeable sheets. First and second supporting members are provided such that each of them is formed of a paper-like sheet formed with a plurality of pleats which have straight trough lines. Each of the pleats of the first supporting member is located facing and spaced from each of the pleats of the second supporting member to form a pair of the facing pleats, defining a pair of facing trough portions. In this adsorbing element, the first and second side edges of each adsorbing sheet are located respectively at the pair of facing trough portions so that each adsorbing sheet is supported between the pair of the facing trough portions.