Abstract: A method for determining the direction of the Earth's magnetic field, which may be interfered with by magnetic materials built into equipment and by electric currents, using an electronic magnetic compass which contains three magnetic field sensors and two devices for measuring inclination is provided. The electronic magnetic compass is arranged in N different spatial positions, in each of these N positions, the inclination sensor signals and the magnetic field sensor signals being measured and inclination values and magnetic field values being determined from these signals. On the basis of these inclination values and magnetic field values, the magnitude of the Earth's magnetic field vector is determined using the vector equationconst=b.sub.g =b.sub.E sin(i)=g.sup.T L(b.sub.E)=g.sup.T m(b.sub.mes -b.sub.o)with ##EQU1## N having to be at least equal to the number of parameters to be determined in the vector equation.