The invention relates to a method for the control of the breathing gas supply, in particular of the oxygen supply, from a pressure-leading supply conduit (1) to one or more breathing masks (3) of an oxygen emergency supply device in an air vehicle, in particular in an aircraft, with which an on/off valve (2) is arranged between the supply conduit (1) and the one or the several breathing masks (3), with which valve the conduit connection can be blocked or released, with which a desired mass flow dependent on cabin pressure is set and the actual mass flow is detected, wherein in a first method step the valve (2) is activated in an opening manner until the error between the actual mass flow and the desired mass flow and which is summed over time exceeds a previously fixed maximal error value (4), whereupon the valve (2) in a second method step is activated in a closing manner until the error between the actual mass flow and the desired mass flow and which is summed over time exceeds of a previously fixed minimal error value (15), whereupon the cycle is repeated beginning with the first method step.