PURPOSE: To confirm guard information from an alarm receiving center by transmitting the guard information when a call is generated within a fixed period after giving up the transmission of the guard information.

CONSTITUTION: A periodical origination control part 103 is provided with a clock in its inside and sends a periodical origination request signal (k) to an information storage part 106. When an alarm or the like is generated and a call is originated within the fixed period after giving up the transmission of guard information to the alarm receiving center, a call control part 108 outputs a status transmission requesting signal l to an information control part 107. Receiving the signal l, the control part 107 outputs a start requesting signal (b) to a network control part 104. Receiving the signal (b), the control part 104 automatically dials the alarm receiving center, and when the dialing is automatically terminated by the alarm receiving center, the center returns a response signal and a data transmitting command. The control part 107 starts to send a timing clock (g). Receiving the timing clock (g), the storage part 106 sends data (f) such as the stored guard information. When receiving the data normally, the alarm receiving center returns a normal end signal.