Bacteria, cancer cells, fungus and other harmful cells located beneath the surface of a mammal body can be effectively destroyed by passing an electrical current through the area to be treated. Electrodes are positioned on either side of the area to be treated, for example, gums, fingers, arms, legs, feet and torso, and an electric current is caused to flow between the electrodes and through the area to be treated. The electric current will destroy the bacteria, cancer cells, fungus or other harmful cells.