The present invention makes it possible to precisely monitor remotely located objects. The construction vehicles each contain a GPS apparatus, and various sensors for capturing the states of vehicle parts, and are capable of reporting, as required, the current position captured by the GPS apparatus, and operation information captured by the various sensors to the TMS mail server via the satellite communication system. The TMS mail server and the rental company system are capable of communicating at any time via a communication network between computers. The TMS mail server collects the latest positional information, operation information, and so forth, on the construction vehicles being rented and relays such information in the form of electronic mail, for example, to the rental company system as required or periodically. The rental company system displays construction vehicles by means of marks in the current positions of the construction vehicles on a map represented by map data, or in the form of a list, based on the collected positional information and operation information, on a branch store computer terminal. The system also displays the operating states of rented construction vehicles based on the collected operation information, on the branch store computer terminal.