To prepare data in the case of displaying a three-dimensional(3D) shape at a high speed.

The 3D shape processor for processing the 3D shape composed of plural 3D shape elements is provided with a circumscribing space area calculating means for finding a 3D space area circumscribing each of 3D shape elements, an inclusive relation judging means for judging the inclusive relation of the 3D shape elements as an inclusive relation of the circumscribing 3D space area, which is found by the circumscribing 3D space area calculating means, corresponding to the 3D shape elements and a partial data deleting means for preparing data for the simplified display of the 3D shape deleting data corresponding to the 3D shape element, which is judged inclusive in the other 3D shape element by the inclusive relation judging means. Thus, the total amount of data for the detailed display of the 3D shape is reduced and the display of the 3D shape is accelerated.