To improve an interactive answering function for a continuous voice and to improve the interactive answering process speed by judging whether or not sentence information constitutes a processing instruction sentence, outputting sentence information to a meaning analyzing means when so and updating word string information in a storage means when not, and generating sentence information again.

Word string information stored in a buffer part 201 is decomposed into clauses. On the basis of the result of a morpheme analysis, the syntax of the word string information stored in a buffer part 201 is analyzed to generate sentence information. It is judged whether or not the sentence information generated by the syntax analysis is a process instruction sentence by referring to restriction conditions, etc. When it is decided that the sentence information is the process instruction sentence, the sentence information is outputted to a meaning analysis part. The process instruction contents specified by the sentence information outputted from the syntax analysis part 203 are extracted. The process instruction contents extracted by the meaning analysis are executed and the result is outputted through an answer generation part.