The measuring device includes a substrate intended to be arranged on an aerodynamic surface; a profiled element connected at one of its ends to the substrate, and configured to be oriented, under the effect of the fluid flow; a magnet that is secured to the profiled element and is configured to generate a magnetic field; and a measuring element that is configured to measure a value of the magnetic field and to convert this measured value of the magnetic field into an angle value indicating the direction of the fluid flow; the measuring device thus making it possible to measure and provide, in real-time, a numerical angle value with which it is possible to define with high precision the direction of the fluid flow relative to the aerodynamic surface.