Abstract: Disclosed is a device and a method for pressure-packaging a container to be processed, which is sealed by a stopper, the device including a cap with a needle, a fluid injector, and a heating cannula, the cap being designed to be applied to the stopper in a tight manner, the needle being able to move so as to pierce a hole through the stopper, the cannula being able to move so as to close the hole by the melting of the material of the stopper, the needle and the cannula being arranged such that the axes of movement thereof are secant at a point located in the stopper, the end of the cannula being convex.