Abstract: A rapid-action switch, especially for the switching of high voltages and rents in plasma physics, magnetohydrodynamics and like technologies in which an explosive force is provided through a consumable electrode within a U-shaped aluminum body separated from a switching electrode and sandwiched between this electrode and a counterelectrode constituting an anvil. An insulating layer between the proximal leg of the aluminum U and a sharp edge on the switching electrode is pierced as this leg is deformed by the explosive to bring the edge into contact with the U and thereby close the circuit. The switching electrode is provided with a channel open in the direction of the aluminum U and separated therefrom by the insulating layer, the channel having a mouth which is narrower than its base and being provided with a continuous prismatic bar extending over the entire width of the U-shaped aluminum body.