To easily and highly precisely determine a characteristic of the thickness, a material or the like of a surveying objective body.

In this shielding body surveying method for surveying the body by emitting a radio wave from an antenna into a medium surface 30a, while scanning the antenna on the medium surface 30a shielding the bodies 1a, 1b, 2, 3, by receiving a reflected signal by the antenna, and by generating a three- dimensional Voxel data using a position (x, y) on the medium surface 30a with respect to reception signal intensity and a reflection time t as coordinates (x, y, t), polarity information of the third Voxel data provided by subtraction processing is image-displayed to allow discrimination with respect to the first and second Voxel data provided by conducting scanning along the first plural scanning lines 4a parallel to the first direction and the second plural scanning lines 4b parallel to the second direction which is perpendicular to the first direction respectively.