A correction method of a geomagnetic sensor in a mobile device comprising: a step in which, in a mobile device having a geomagnetic sensor, position detection means for detecting a position of the mobile device, and a controller operable to control the geomagnetic sensor and the position detection means, the position detection means detects a predetermined position change; and a step in which the controller starts a correction process of the geomagnetic sensor based upon the detection, wherein the geomagnetic sensor comprises a three-axis geomagnetic sensor, wherein the correction method further includes: a step of starting a correction process of the three-axis geomagnetic sensor on a first plane based upon detection of a first position change of part or all of the mobile device that includes a rotational movement on the first plane; and a step of starting a correction process of the three-axis geomagnetic sensor on a second plane different from the first plane based upon detection of a rotational movement of part or all of the mobile device on the second plane, wherein the first plane and the second plane are provided on the basis of a coordinate system predetermined for the three-axis geomagnetic sensor, and wherein the position detection means includes an acceleration sensor. a step in which, in a mobile device having a geomagnetic sensor, position detection means for detecting a position of the mobile device, and a controller operable to control the geomagnetic sensor and the position detection means, the position detection means detects a predetermined position change; and a step in which the controller starts a correction process of the geomagnetic sensor based upon the detection, wherein the geomagnetic sensor comprises a three-axis geomagnetic sensor, wherein the correction method further includes: a step of starting a correction process of the three-axis geomagnetic sensor on a first plane based upon detection of a first position change of part or all of the mobile device that includes a rotational movement on the first plane; and a step of starting a correction process of the three-axis geomagnetic sensor on a second plane different from the first plane based upon detection of a rotational movement of part or all of the mobile device on the second plane, wherein the first plane and the second plane are provided on the basis of a coordinate system predetermined for the three-axis geomagnetic sensor, and wherein the position detection means includes an acceleration sensor. a step of starting a correction process of the three-axis geomagnetic sensor on a first plane based upon detection of a first position change of part or all of the mobile device that includes a rotational movement on the first plane; and a step of starting a correction process of the three-axis geomagnetic sensor on a second plane different from the first plane based upon detection of a rotational movement of part or all of the mobile device on the second plane, wherein the first plane and the second plane are provided on the basis of a coordinate system predetermined for the three-axis geomagnetic sensor, and wherein the position detection means includes an acceleration sensor.