A safety device for a high-frequency surgery appliance that includes at least one high-frequency generator with an active output and a neutral output to generate a working current, and at least two working connectors. At least one instrument, through which the working current is conducted to a biological tissue, is connected to respective working connectors. The safety device reduces the danger presented by fault currents that may flow through an inactive instrument. The safety device is connected to the active output as well as to the neutral output in such a way that every working connector through which no working current is flowing is connected only to the neutral output.
