A device for the in situ angular positioning of an incidence probe, e.g., of the weather vane type, equipped with a vane and mounted, e.g., on an airplane. According to the device, the axis of rotation of the probe is used directly as a positioning reference. The angular-positioning device include a fixed structure secured to the wall of the airplane, of annular shape and including a circular track for a moving slider. The vane is immobilized in an enveloping structure. A coupling member coupling the slider and the enveloping structure is fixed to the enveloping structure. Coupling is afforded by a flat spring leaf including a stud at its end. The stud is slipped into a slit of the slider, which allows the vane to be driven about its axis of rotation. The position is measured using a digital inclinometer.