To provide an emergency reporting system dispensing with the direct power source management of a reporting button device or master machine by a user or its family and reduced in the cost necessary for management.

The reporting button device transmits, in the capacity shutoff or capacity restoration of a power source part consisting of a built-in battery power source, power source information showing it to the master machine 3 by a wireless signal. The master machine 3 transmits, in the service interruption or restoration of a commercial power source AC supplied as operating power source to the master machine 3 or the capacity shutoff or restoration of a backup battery power source, the power source information therefor and, when receiving the power source information from the reporting button device, the power source information concerned to a management server 1 by a code signal consisting of a PB signal string through a public telephone network 2a. The management server 1 determines the content of the power source information from the received code signal string, generates an e-mail responding to the content, and transmits the generated e-mail to the mail address of the family corresponding to the user of the master machine 3 and the reporting button device 5 to report the state of power source.