PURPOSE: To limit a retrieval range in retrieving and to increase the retrieval speed by storing information indicating in what screen grid the position of each picture element is existed, storing the content including the coordinates of graphic element in correlation therewith, and retrieving and extracting arbitrary information.

CONSTITUTION: This CAD system is provided with a screen layout data base 4 for storing information indicating in what place on the screen of graphic display 6 graphic elements are existed. Further, the display screen for displaying graphic elements on the graphic display 6 is divided into an arbitray number of segments, and a data registration device 2 is provided with a grid range discrimination processing section 2-1 for discriminating in what segment range of the divided display screen the graphic element input from a data input device 1 is existed. Furthermore, a data extraction device 3 is provided with a retrieval grid range selection processing section 3-1, and a data retrieval section 3-2 for retrieving a graphic element from the screen layout data base 4 and a graphic element data base 5. Thus, the retrieval range is limited and futile processing can be reduced.