A compression piston switch is provided with two switching parts which are mutually axially displaceable. The switch also has a device which is connected to a first one of the two switching parts for guiding a quenching gas flow. The quenching gas, which is used for quenching a switching arc, flows through first and second constrictions in the device from a compression into an expansion space. The first constriction of the device is provided by an annular part of a conductive material.In this switch, the dielectric strengthening of the quenching zone is increased by preventing, to a large extent, the pushing together of the electric field between the device and the first switching part. Such a switch is particularly distinguished by reliable switching of high voltages in the case of a short circuit.