A highly-insulated power source used in an electric potential therapy device and an electric potential therapeutic device using an insulation transformer capable of performing insulation of several thousand volts and in small size, light weight, and low cost are provided. The electric potential therapy device comprises a first primary coil, a second control circuit and a heater transformer, wherein an AC voltage generated in a first control circuit for generating an AC voltage by switching a DC voltage of a power supply circuit is input to a first primary coil and boosted； then the AC high voltage is output to a high voltage transformer with an electricfying sheet from the first primary coil； the second control circuit can generate AC voltage via DC voltage of a power supply circuit by switching； a second primary coil can be connected with the first primary coil via the heater transformer； AC voltage generated by the second control circuit can be input to the second primary coil for voltage switch, so AC voltage of the second primary coil can be rectified and smoothed and output to the heater； the second and first primary coils are winded by the heater in an iron core； and the iron core is made of Ni-Zn.
