GEOMAGNETIC DEVICE

A geomagnetic application device comprising a triaxial magnetic sensor, a measurement point acquiring means, a calibration means for calibrating offset of the magnetic sensor, and an azimuth calculation means, is provided. The geomagnetic application device is characterized in that the calibration means is provided with an offset calculation measurement point selection means for selecting at least six measurement points of the geomagnetic vectors from among a data set stored in the measurement point storage unit by the measurement point acquiring means and storing the selected measurement points in an offset calculation measurement point storage unit, and that the offset calculation measurement point selection means select the measurement points from among the data set stored in the measurement point storage unit so as to include at least six points, the component values of which are maximum or minimum in each of the three orthogonal axes.