The plasma generating apparatus (1) is provided with a simple switching circuit (3) for generating AC power of high frequency by a magnet (16) for switch driving use for repeating the excitation and the demagnetization by AC power and a contact switch (S) to be opened or closed by the magnet (16), a simple voltage transforming circuit (4) for converting AC power of high frequency outputted from the switching circuit (3) into AC power of high voltage, a discharge electrode (5) for receiving AC power of high frequency and high voltage outputted from the voltage transforming circuit (4) to cause corona discharging, when the opposite electrode has been approached, to cause the plasma. The plasma producing apparatus (1) is easier to be carried, because the switching circuit (3), the voltage transforming circuit (4), and the discharge electrode (5) are respectively simple, compact in construction. The apparatus (1) becomes smaller in power capacity and is reduced in cost.