To aim at autonomously selecting and switching over a management system by a terminal device, and preventing the terminal device from switching over the system, managing the self-terminal, to a backup system even in the case of a temporary fault from which to recover relatively immediately and in the case of occurrence of an inconvenience (trouble) negligible enough not to be treated as the fault. Included are a terminal device 21 transmitting, a registration request (S101) to a backup system 1b, if a fault occurs in a main system 1a, and the backup system 1b not providing a management service even when receiving the registration request (S101) till a startup request (S204) made by a monitoring server 18b is received.