GEOMAGNETIC SENSOR

A geomagnetic sensor includes: a core 10 that constitutes a closed magnetic circuit; a pair of coils 21, 22 that are wound around the core 10 in positions facing each other and are connected in series to generate magnetic flux in the same circumferential direction in the core 10; an excitation power supply 30 that applies an AC current with a superimposed DC current to the pair of coils 21, 22; and a detection circuit 40 that is connected to a connection point P of the pair of coils 21, 22. Unlike a conventional flux gate type geomagnetic sensor, it is not required to excite the core until the core is magnetically saturated, and it is therefore possible to reduce power consumption.