A device for measuring a volume flow, especially a tidal volume flow sensor, with a flow channel (1) and with a sensor element (6) arranged within the flow channel (1), is shown and described. The task of providing such a device, in which the sensor signal, which is generated by sensor elements arranged in the flow channel, remains as free as possible from distortions during the transmission to an evaluating unit, is accomplished by providing an internal circuit (3), which is arranged within the flow channel (1) and includes the sensor element (6). An external circuit (7) is arranged outside the flow channel (1). The external circuit (7) is designed for contactless, inductive coupling with the internal circuit (3) for supplying same with energy and for reading.