Abstract: An apparatus for measuring the flow rate of fluid media has a rod-like interfering body rigidly arranged in the flow and which has a cylindrical flow-against surface on which periodically separating eddies form, as well as a device with a sensor for recording the eddy separating frequency which is dependent on the flow rate. In order to obtain a proportional dependence between the flow and separating frequency over a wide Reynolds number range in the case of a low inherent flow resistance, the interfering body is symmetrically bent downstream and to either side from its top. To avoid interactions between the two vortex paths which form, a diverting surface is positioned behind the interfering body in the plane thereof.