A decompression device has at least one decompression member which is arranged on a supporting structure and which, in the event of differential pressure of a predetermined level, opens an opening in the supporting structure that acts as a connection between two volumes, wherein the decompression member can move between a retention position, in which the decompression member closes the opening, and a released position, in which the decompression member opens the opening, and has a locking arrangement which, when in use, fixes the decompression member in the retention position. The locking arrangement is provided with at least one locking element, which is arranged on the supporting structure, and the decompression member is kept in the retention position indirectly by the locking element interacting with an air conduction part.