PURPOSE: To utilize the data stored in a knowledge base to the generation of the data on the next objective object model by producing a data base from the model data on an objective basic object.

CONSTITUTION: A command and its parameter are inputted via an input/display means and an objective basic object model data 31 is produced at a basic object model generating part 21 and stored in a data base 30. Then the conversion data generating part 221 of an inference processing part 22 infers the similarity between the data 31 and the object model data 42 through matching of their structures and attributes and based on the existing meta-data 41 stored in a knowledge data base 40 as well as the data 31 and the data 42. Thus the model conversion data 32 is produced and stored in the base 30. Then an object model generating part 23 calls out both data 32 and 31 to the base 30 and the data 33 on the produced subject object model is produced at the base 30.