A device for measuring the permeability of fluids and/or vapors through elastomeric seal bodies comprising a container incorporating a recess for holding a test medium, the recess being covered and closed off by a lid by way of screws fastening the lid to said container, wherein the seal body is positionable between the end face of the container and the face of the lid, both surfaces being places so as to face each other, and lockable in position by way of screws using a predetermined load force, and the test medium is measurable as it passes to the exterior through the remaining material thickness of the seal body through a seal gap between the front faces.