To improve the convenience of use, by setting a datum point at the position of a shrine located at a vertex of a regular triangle drawn on the ground surface by the spherical trigonometry, fitting to a stone marker and displaying on a drawing.

A regular triangle is formed based on a site where a shrine is located on a level ground, by connecting the site of the shrine and a mountaintop for a mountainous region and by connecting the site of the shrine and island points for a coastal region. A wide-range network is constructed. A control point 10 based on the actual survey is set at the present site of the shrine which is located at a vertex of the regular triangle constituting the network, and fitted to a stone marker 11. The stone is embedded at the center of a name plate 16 of a regular square. A longitude and latitude, and elevation plate 17, a coordinate plate 18, an azimuth plate 19 and a management plate 20 are rigidly fixed altogether in the periphery.