Abstract: The invention relates to a device for drying a gas, in particular air, that comprises at least one chamber (5) with an inlet (a) for the flow of gas to be treated and an outlet (5b) for the flow of treated gas, said chamber being limited by at least one membrane (6) having a water vapour perviousness that is significantly higher than the perviousness to other gases or vapours, a humidity absorbing material being provided or flowing against the membrane (6) on the side opposite the chamber. The device includes a stack of plates (P1, P2) provided with central openings (A, B); each chamber (5) is formed by a central opening (A) located between two parallel membranes (6) while the humidity absorbing material is provided against each membrane (6); each plate (P1) is sandwiched between two plates (P2, P3) including a housing (B, B1) for the humidity absorbing material; and a plurality of chambers (5) are stacked and connected in series.