PURPOSE: To provide an apparatus capable of generating ions and ozone in a coexisting state by selecting a polarity, by equipping an alternating current high voltage generator, a rectification circuit and corona discharge electrodes to generate cations or anions.

CONSTITUTION: An alternating current high voltage generator 1 consists of an oscillating circuit O and a step-up transformer T and generates an output voltage of high voltage and high frequency (e.g. 6KV and 2KH at maximum) in the secondary side of the step-up transformer T. The output voltage is charged on the diode D in a rectification circuit 2, a negative voltage is charged on an upper discharge electrode 3 of a corona discharge electrodes, a creeping discharge is generated around the discharge electrodes by discharging in a way of increasing negative voltage as shown in the wave figure and anions and ozone are generated. In the figure, Z is an impedance which inhibits a short circuit current in case when a forward direction voltage is charged to the diode. When the diode D is connected in an opposite way to the figure, a negative voltage is charged on the upper discharge electrode of the corona discharge electrodes and anions and ozone are generated around the discharge electrode.