To reduce a risk that a lost guest card is used.

A terminal device 11, when a guest card 13 is lost and reissued, outputs identification information to identify an electric lock device 3 that can be used by the reissued guest card 13, and also outputs an alarm receiving alarm information from the electric lock device 3 when the lost guest card 13 has been used. The electric lock device 3 connected to the terminal device 11 online, upon receipt of the identification information from the terminal device 11, updates and stores the identification information while storing previous identification information before update, and outputs the alarm, warning that the lost guest card 13 has been used when the identification information of the lost guest card 13 matches the identification information before update, and transmits the alarm information, warning the same, to the terminal device 11.