The present invention prevents electric shock to a treatment subject, secures the safety of the treatment subject, and easily obtains a sensation of stimulation and a sensation of treatment by means of an AC source. The electric potential treatment device (1), which performs treatment by means of placing the treatment subject within an electric field, is characterized by having: a primary electrode (2) disposed spaced from the treatment subject a first contact electrode (3) and a second contact electrode (4) disposed in a state contacting the treatment subject and a voltage generation unit (5) that, with respect to the electrodes, increases the voltage of the commercial power source voltage and supplies a predetermined AC voltage. The electric potential treatment device (1) is further characterized by a high AC voltage for treatment being imparted to the primary electrode (2) by means of the voltage generation unit (5), a low AC voltage being imparted to the first contact electrode (3) and the second contact electrode (4) by means of the voltage generation unit (5), and a weak current (i) being caused to flow through the treatment subject by means of the potential difference between the contact electrodes.