A device for applying a high voltage using a pulse voltage is provided which applies a high voltage having a pulse width τ0 to a capacitive load (1) through a pulse transformer (4), the high voltage having pulse-like peaks with a steep leading edge, wherein a capacitance C1 of the capacitive load (1) and a secondary side leakage inductance L1 of the pulse transformer (4) satisfy the equation: L1=(τ0/π)2×(1/C1). This enables enlargement of the pulse-like peaks and application of any pulse repetition frequency when the high voltage having the pulse-like peaks is applied to the capacitive load through the pulse transformer.