Provided is a method of generating a magnetic field map including obtaining magnetic field information, the magnetic field information being information on a magnetic field affecting a mobile body, for each position of the mobile body, and building a magnetic field map based on the magnetic field information for each position of the mobile body. The pose of a mobile body can be statistically checked by the probability obtained using the difference between the magnetic field information observed from the magnetic field map and the actually measured magnetic field information. Although the pose of the mobile body is estimated using a camera that is sensitive to an illumination state where the mobile body is placed, the pose of the mobile body can be relatively accurately checked using the magnetic field map obtained in a situation regardless of illumination, with being less affected by the illumination state where the mobile body is placed. Thus, the pose of the mobile body can be checked with reliability.