PURPOSE: To store an object into an exclusive object in a knowledge base system by sorting automatically the object based on the slot value of each object.

CONSTITUTION: The sorting object is generated by a sorting mechanism initialization means 7 when a knowledge base is generated. When a user sets the items for sorting through a sorting setting means 8, the sorting items corresponding to the sorting objects are produced as the object slots. In an execution state, the contents of the knowledge base are corrected by a data setting means 9, a data deleting means 10, a data element adding mans 11, and a data element deleting means 12 so that the correspondence is secured between the value set at the sorting item slot of each object to be sorted and the object pointer in the corresponding item of each sorting object.