To structure the semantics of a sentence in the same way as a human being understands.

The part of speech/conjugation of each word of an inputted sentence is defined, the related destination attribute/receiving source attribute of each clause constituting the sentence are further defined and relating and receiving relation between respective sentences are defined, the clause is decided as a node of a binary tree from the relating and receiving relation between clauses of the sentence, semantic calculation information is added to each node of the binary tree by using a dictionary 8 for a semantic analysis after generating a binary tree structure representing the relating and receiving relation between the clauses, the results of a dyadic operation performed to two nodes constituting the binary tree are recorded on an upper node on the basis of a computing type attached to each semantic attribute in the case a semantic calculation condition attached to each semantic attribute is satisfied concerning each semantic attribute described in semantic calculation information on the basis of the semantic calculation information attached to each node, is recorded in an upper node, and such an operation is performed to all of the nodes. Thus, the semantics of a sentence can be structured in the same manner as a human being understands.