PROBLEM TO BE SOLVED : To provide technology for reasonably managing a tenant by using real estate rental and Internet connection service in that real estate.SOLUTION : To provide a management server comprising : registration data transmission means for transmitting registration data that a communication terminal concerning the real estate tenant requests user specification data for primarily specifying a real estate tenant in order to perform communication connection; a MAC address database for receiving and registering the user specification data input from a communication terminal which receives the registration data and a MAC address of the communication terminal; address determination means for receiving the MAC address transmitted from the communication terminal which receives radiowaves transmitted from a router and determines whether or not the MAC address is registered in the MAC address database; and a communication management database which continues communication, and accumulates communication record data including time when the communication is completed when the address determination means determines that the MAC address is registered.COPYRIGHT : (C)2015, JPO&INPIT