Abstract: A low frequency medical treatment apparatus comprising an over-current preventing measure with an overcurrent detecting circuit and a switching circuit to control an output transmission path according to the detection output, a shock preventing measure having a control circuit for opening or closing an output wave transmission path in response to a switching element whose operating state is changed depending on whether or not an output controller is set at its minimum set position, and a measure of improving comfortability in use having a circuit for controlling the output wave transmission upon contact of a touching element with human body and a circuit for maintaining the output waveform unchanged.