A method for measuring current in an electric network comprising at least one first electric line. The method includes fitting the first line with a circuit breaker having a protection coil and having a wall traversed by a magnetic field emitted by the protection coil; arranging on the wall of the circuit breaker a synchronous three-axis digital magnetometer on a semiconductor chip; by way of the digital magnetometer, measuring at least one component of a magnetic field emitted by the coil; and determining the value of a current traversing the electric line from the measured component.