An ozone generating apparatus that includes a plurality of adjacently stacked ozone generating units. Each unit includes two electrodes, mutually opposed, to generate a voltage discharge in response to applied high voltage. A dielectric is interposed between the electrodes to provide insulation. A gas supply mechanism to supply an oxygen-containing gas between the electrodes is provided to generate ozone by the voltage discharge. An electrode from adjacent units define a sealed space to pass the gas only between the electrodes of the ozone generating units and through the adjacently stacked ozone generating units.
