PURPOSE: To provide an interactive processor capable of sharing the same subject with an interactive party, mutually transferring questions and explanations to/from the interactive party and dynamically setting up a subject in accordance with the advance of interaction.

CONSTITUTION: The contents of talks are determined based upon a task rule data base 10 for regulating the contents of talks corresponding to the advancing state of interaction, an interaction rule data base 20 for regulating the type of talks corresponding to belief relating to the interaction and a change due to talks in the belief relating to the interaction, a belief data base 30 for storing information relating to the interaction and the belief relating to the interaction, and the advancing state of the interaction. The interaction processor consists of a talk processing means 40 for determining a talk type based upon belief relating to interaction and storing talk information and belief to be changed by talk in the belief data base 30 and a terminating call processing means 50 for storing a terminating call type extracted from a terminating call from an interactive party and updated belief relating to the contents of talk and interaction in the data base 30.