PURPOSE: To facilitate the control of a model by dividing modeling space, and coordinating an identifier and a model element with each other in every partial space.

CONSTITUTION: In data structure to show the correspondence relation of the partial space, an identifier table and the model element, a pointer 23 to point an area where the identifier table 22 is stored is registered in accordance with a partial space name 21 attached to the partial space. The identifier 24 and the pointer 26 pointing the area where the model element 25 corresponding to this identifier 24 are registered in the identifier table 22. Then, by giving the partial space name 21 and the identifier 24 by a user, the desired partial space can be specified, and further, the desired model element can be specified. Accordingly, the user need only control the identifier 24 for every partial space, and the control of the identifier 24 becomes easy. Thus, the control of the model becomes easy as well.