PURPOSE: To enable the wide reuse of a developed object by noticing relational structure between objects.

CONSTITUTION: In the case of describing an object, the grammar of the object is determined so that declaration information 10b indicating relation with a different object is described by a format separated from the description 10c of the function attaining part of the object itself. An object managing means 13 stores information relating to the relation with the other object in an object storing part 17 separatively from the information of the function realizing part of the object itself and manages the stored contents based upon the description. A relational structure display processing part 15 display information relating to the relational structure and an object editing processing part 16 is allowed to simply utilize other objects by operating the display.