To provide a monitoring device of an unmanned helicopter capable of preventing the operation of a working device in a place other than a predetermined place (a working range), and preventing theft.

The monitoring device acquires position information related to the position of a helicopter body of an unmanned helicopter 1 acquired from a GPS, and compares the position information with a preset working range to determine that the helicopter body is inside or outside the working range. When the helicopter body is within the working range, the working permission signal to permit the predetermined work is transmitted to the unmanned helicopter so as to perform the work. When the helicopter body is outside the working range, the work prohibition signal to prohibit the predetermined work is transmitted to the unmanned helicopter to prohibit the work.