The information terminal device, information communication method, and an information communication program

In the information sharing system including a plurality of information terminal devices, while allowing a change in the roles of the information terminal device, to allow sharing of information in response to user demands for each information terminal. A plurality of information terminal device by being capable of transmitting and receiving setting information to each other via a communication network, configuring the information sharing system. When functioning as an information providing terminal device, the information terminal device, in response to a request from the information receiver of the information terminal device transmits the provided information list to another information terminal device. When receiving a request for providing information from another information terminal device, the requested advertisement, and transmits to the information terminal apparatus that has transmitted the least the request. On the other hand, if the function as the information receiving terminal device, the information terminal device requests providing information list to the information provider of the information terminal device. When receiving the provided information list, a request for providing information specified by the user, and transmits to the information provider of the information terminal device.