Abstract: The present invention relates to a process and a device (1) to test the sealing of cork stoppers (R). The device (1) comprises a partitioning mechanism dividing a chamber in two compartments (8a, 8b). The partitioning mechanism comprises: an adjustable insulator (9) configured to hermetically seal a central part of the stopper (R) from the outside environment and simultaneously to arrange each end of the stopper (R) in one of the compartments (8a, 8b); and an insulator actuation member (10) to arrange the insulator (9) on the central part of the stopper (R). The device farther comprises a block (11a) for closing the compartment (8a); an inlet (12) connected to a test fluid source, the source arranged in the block (11a), and a detection member (13) connected to the same block (11a). The present invention finds application in the field of cork stopper production and in the cork industry in general.