The present invention relates to a gas-selection device (1) for a sealed storage container (100) with modified or controlled atmosphere, remarkable in that it comprises a hollow body (2) and at least one first orifice (3), a second orifice (4) and a first membrane (5), said first and second orifices (3, 4) connecting the inside of said body (2) to the outside, said first membrane (5) being disposed inside said body (2) between said first and second orifices (3, 4) so that the gases flowing from the first orifice (3) to the second orifice (4), or vice versa, necessarily and solely pass through said first membrane (5), and in that the device (1) is arranged so as to be secured sealingly to one (101) of the walls of the container (100), so as to allow a flow of gas from its second orifice (4) through the wall (101), or vice versa.本發明關於一種氣體選擇裝置（1），用於具有改良或受控制的大氣之密封的儲存容器（100），氣體選擇裝置的卓越之處在於，其包括中空的本體（2）及至少一個第一孔口（3）、第二孔口（4）及第一薄膜（5），第一及第二孔口（3、4）連接本體（2）的內部到外部，第一薄膜（5）在第一及第二孔口（3、4）之間被設置在本體（2）的內部，使得從第一孔口（3）流動到第二孔口（4）或反向地流動的氣體必然且完全地通過第一薄膜（5），且氣體選擇裝置（1）被佈置為被密封地固定到容器（100）的一個壁（101），以允許氣體從其第二孔口（4）通過壁（101）流動或反向地流動。
