An electrolytic treatment method in which a predetermined treatment is performed using treatment subject ions contained in a treatment liquid, the method including: an electrode positioning step for positioning a direct electrode and a counter electrode so as to sandwich the treatment liquid, and positioning an indirect electrode for forming an electric field in the treatment liquid; a treatment subject ion migration step for applying a voltage to the indirect electrode and thereby moving the treatment subject ions in the treatment liquid to the counter electrode side; and a treatment subject ion redox step for applying a voltage between the direct electrode and the counter electrode and thereby oxidizing or reducing the treatment subject ions which have migrated to the counter electrode side.