To quickly, simply and effectively utilize a map displayed on a mobile apparatus by a map information service.

A direction magnet 4 is provided at a strap A to be mounted to the mobile apparatus, thereby a direction at the place of a direction which becomes reference is known by the magnet 4. Thus, only by looking at the map displayed on the basis of this direction, the direction of a destination is known. As the result, the map can quickly, simply and effectively be utilized.