To provide an apparatus for electrotherapy wherein cancer cells are selectively destroyed, effects of using the apparatus are visible in a short time, and regenerative healthy tissues are not damaged.

The apparatus for electrotherapy generates a current with a frequency of 300 kHz to 1 MHz and affects a human body using an activating electrode and a feedback electrode. The apparatus is equipped with the feedback electrode which comprises a flat metal plate, the activating electrode smaller than the feedback electrode which comprises a flat metal plate molded according to the tissue of the body to which the apparatus is a attached, and a power-amplifying high frequency oscillator which generates appropriate frequency.