The generation of high voltage pulses with short leading edges (~1 ns) has numerous applications and is a topical task for modern science and technology. One of the main elements in this process is a switching device capable of passing from non conducting to a highly conducting state within a minimum possible time. A rather exhaustive review of these devices is given in monograph [1], according to which the gen eration of high voltage pulses with short leading edges and high (f > 10 kHz) repetition frequencies is still among the unsolved problems. In recent years, progress in this field has been achieved predominantly due to the development of new solid state switches such as semiconductor step recovery (snap off or charge storage) diodes [2,3]. This Letter presents the results of an investigation of the possibility of switching pulses with leading edge widths below 1 ns with the aid of open discharge (OD), which was originally used for the generation of short intense electron beams in the keV energy range [4] in gases at medium pressures [5]. Recent achievements in this field have made possible the creation of com pact devices capable of generating pulsed electron beams with nanosecond durations [6] at energies up tõ 10 keV and current up to ~25 kA, which are promis ing sources for the excitation of various lasers [4,7] and some other applications [8][9][10]. In these devices, the OD is initiated in a narrow (0.2 to 10 mm wide) accelerating gap between continuous cathode and grid anode, from which electrons enter an extended drift space. A principal feature that distinguishes OD from discharges of other types is that the former operates under conditions where the main kind of electron emission from the cathode is the photoemission under the action of resonant VUV radiation of a working gas [6,11]. This regime of emission automatically ensures a long working life of the cathode and high efficiency of electron beam generation.The OD is usually operating in the region of work ing gas pressures from units to several dozen Torr (depending on the gas type) [11]. Under these condi tions, the gap breakdown proceeds according to the exponential law with a significant delay t d relative to the moment of voltage application, while the break down (i.e., switching) time t sw is much shorter than t d .[12]. The small interelectrode gap ensures rapid de ionization of discharge plasma, which allows electron beam pulses to be generated at a repetition frequency of up to 10 6 Hz [13]. Therefore, the OD can serve a basis for the creation of current and voltage pulse shapers capable of operating at high repetition fre quencies.The experiments were performed in a discharge cell with coaxial electrode geometry analogous to that recently employed in [6]. The internal diameter of a SiC cathode was 50 mm, the interelectrode gap width was 3 mm, and a grid anode has a diameter of 44 mm, a length of 20 mm, and a geometric transparency of μ = 0.9. The shaper was excited by the circuit sche matically depicted in Fig. 1a. Figure 1b presents w...