Abstract: A device for ensuring the safety of the oxygen and gas supply to a welding and cutting torch (4). The object of the device is to prevent accidental escape of oxygen and/or gas when the torch is not in use. For this purpose, the device is characterized in that the oxygen supply line and the gas supply line each contain a controlled regulating valve (10, 12), which valves are connected to a common control line (14). The oxygen supply line, downstream of the regulating valve (12), viewed in the direction of flow of the oxygen, contains a starting tank (20), and a flow-pressure switch (21) which operates a regulating slide valve (16) accommodated in the control line, said control line being in communication by way of the regulating slide valve and a line (30) with the part of the oxygen supply line situated upstream of said regulating valve (12).The invention is also embodied in a flow-pressure switch, which is suitable in particular for use in the above device.