A current sensor using a resonance directional magnetometer which includes a magnetic circuit having a gap and a device supplying a voltage representative of a magnetic field produced in the gap by a current when the current passes through the circuit. The value of the field is a function of the intensity of the current. The device is a resonance directional magnetometer having a sample with resonant spins placed in the gap and exposed to a magnetic field having a polarization parallel to the field produced in the gap or coinciding with this field and a measuring device for exciting the resonance and detecting the excited resonance and for supplying a voltage representative of the amount of excited resonance.
