To facilitate an input operation in a communication terminal, to permit the diversification of an input content in the communication terminal and to extend the range of choices which can be selected in the communication terminal at the time of advancing a processing by an interactive method between an information supply server and the communication terminal.

A response with voice at the communication terminal 101 is permitted with respect to a question included in supply information referred to by the communication terminal 101. Response information by a voice signal system, which is inputted with voice is voice-recognized and it is converted into response information of a data system, which an information supply server 102 can recognize. In the information supply server, the question or the response in a next stage is led based on converted return information and supply information including information is generated. A processing by the interactive method between the information supply server 102 and the communication terminal 101 becomes possible. The response with respect to the question can be inputted with voice in the communication terminal 101.