A high-frequency, high-voltage electron switch includes an electron source, a steering mechanism, a mask or anode plate, and a target. The electron source produces a beam of electrons with a voltage of at least about 1 kV that impinges upon the anode plate. The steering mechanism scans the electron beam across the anode plate at a scanning frequency of at least about 10 MHz. A hole or aperture is provided in the anode plate that allows the electron beam to pass through and produce a pulsed, high-voltage current in the target with a very high-frequency repetition rate and a very fast rise time. The pulsed, high-voltage current produced in the target can be used to cause a high-voltage source to turn on and off.