PURPOSE: To provide a device by which a user, to recognize the forwarding of its own luggage with a portable sensor at a distant place avoiding surrounding congestion and which can be utilized as the alarm for leaving a thing or the like by composing the device of a radio transmitter with an automatic control part and a radio receiver with automatic inverse control part.

CONSTITUTION: A radio receiver (b) with automatic inverse control part is carried by an individual, and a radio transmitter (a) with automatic control part is fitted on the side of luggage. When the device is deposited on an aircraft as luggage, a power source 9 of the transmitter (a) is automatically turned off by the functions of sensors 4 and 5, electronic switch 6 and time limit switch 7 inside the transmitter (a) inside the aircraft and, when the luggage is put down on the ground after landing, the power source 9 is automatically recovered to radiate radio waves for alarming the reception of luggage. When a power supply switch 8 is turned off in this case, the power source 9 is supplied to the time limit switch, and the power source is outputted after the lapse of a fixed time. The sensor 4 is a circuit provided with a photosensor and does not turn on the electronic switch 6 in the dark viewing state and the sensor 5 turns off the electronic switch 6 with the roar of the aircraft.