[Problem] to provide real estate rental contract communication business activity can be performed in a timely manner, the user can quickly perform maintenance contract communication environment. [Solution] a real estate agent assigned to store the required information to the communication network 400 is connected between terminal 100 tablet is. Real estate rental contract specific real estate rental information indicating whether the communication environment of the scheduled maintenance of basic information, and, real estate rental contract establishment to specify additional information reception section 240 and the target object, the control information and the information storage part 280, new communication contract information is included when determining, a plurality of sets of registering new subject matter information registration section 270 retrieves the line contract line contract information corresponding to the obtained retrieval section 260 and contract information communication, basic information on the terminal device 100 is stored in information storage section 280 of each tablet with a delivery part 214. Figure 3 [drawing]