<p>The liquid supplied to an emitter electrode located at a tip of an atomization nozzle receives the high-voltage and electrically charged. The mist of the charged minute water particles of nanometer sizes is generated from the emitter electrode. A pressure regulating means regulates a pressure applied to the liquid on the tip of the emitter electrode. Therefore, the mode of generating the mist of the charged minute water particles of nanometer sizes or the mode of generating the mist of the charged minute water particles of nanometer and micron size is selected.</p>
