PURPOSE: To enable an effective treatment by detecting an exact spot for applying treatment, by providing a current ratio detecting circuit wherein a current ratio between an initial current value flowing between electrodes to be applied to a living body and a current value flowing thereafter is detected, and judging it.

CONSTITUTION: A main body 5 is proorded with terminals 10, 11 for giving voltage to a living body 14, a function of calculating a current ratio between an initial current value flowing in the living body and a current value flowing thereafter, a meter 9 for displaying the current ratio, a function for calculating the resistance of the living body based on the current flowing in the living body, a plate 8 for displaying the value, and a buzzer 7 for giving alarm when the value becomes higher than a value selected by a limit switch 6. A hand piece 12 is provided with a probing electrode 13, which is connected to the terminal 11. The probing electrode 13 is moved under pressure on the skin of the living body for seeking a spot effective for treatment. A positive voltage is applied on the probing electrode 13 for seeking an effective spot for treatment, and a non-probing electrode 15 has a larger surface area for passing current.