Abstract: There is disclosed a method comprising an external data entering step (A), a shape data dividing step (B) for dividing the external data into cubic shape cells 13 having boundary planes orthogonal to one another based on octree division, and storing shape data for each cell, and a physical quantity dividing step (C) for dividing a physical quantity of the object into different physical quantity cells 13? for each physical quantity based on octree division, and storing each physical quantity for each physical quantity cell. The shape cell 13 and each physical quantity cell 13? for each physical quantity are stored on different memory layers 18 in the same coordinate system, and managed in correlation with each other. In addition, the plurality of memory layers 18 are used singly or in combination for use of the data of the shape and the physical quantity.