An oxidation and reduction fine particles generator includes an atomization electrode, a water feeder for supplying water to the atomization electrode and a high voltage generator, and also includes a switch device and a controller. The switch device changes an operation mode to an oxidation mode or a reduction mode. The controller generates negatively charged fine water particles including radicals through electrostatic atomization by applying a high voltage to water supplied to the atomization electrode in the oxidation mode. The controller also inactivates and activates the water feeder and the high voltage generator, respectively to generate reduction fine particles from the atomization electrode by dry discharge in the reduction mode.