There is provided a Bluetooth module part for establishing wireless connection to a cellular telephone having a Bluetooth function and a microcomputer for determining that the cellular telephone has been left when connection to the cellular telephone has continued for a certain time, and the cellular telephone is provided with any one of a function of providing unique information identifying the self and a function of obtaining present position information of the self, and there is provided the microcomputer for sending at least one of a device ID and the present position information to a preset communication destination through the cellular telephone when the microcomputer determines that the cellular telephone has been left.