Voltages are applied to a plurality of electrodes each connected to a plurality of electrode connection parts, by employing a voltage application device comprising: an electrode circuit including the plurality of electrode connection parts connected in series via a resistance R between neighboring electrode connection parts; and power sources P capable of outputting a voltage of both positive and negative polarities, the power source each being connected to both ends and at least in one intermediate position of the electrode circuit. The method of applying a voltage comprises: determining a polarity and a magnitude of an output voltage of each of the plurality of power sources P so that a voltage having a predetermined polarity and magnitude is applied to each of the plurality of electrodes; and based on the polarities of the output voltages of the plurality of power sources P, switching the polarities of the output voltages of all the power sources P by switching the polarities of the output voltages of the plurality of power sources P one at a time while maintaining a state where a polarity of an output voltage of at least one power source P, among the plurality of power sources P, is different from others.