Abstract: Method and apparatus for measuring an entity of a magnetic field using a Hall sensor which is provided with at least one Hall plate which has a group of two pairs of terminals located at a distance from one another, an excitation signal supplied from a source to one pair of terminals and a detection signal, which forms a representation of the entity, which is tapped off from the other pair of terminals by a processing circuit. The source is a voltage source of which an impedance is negligible for use of the sensor, and the processing circuit has a negligible input impedance for tapping off me detection signal as a short-circuit current.