PURPOSE: To accurately monitor aerial preservation lighting facilities by synthetically judging the state of the aerial preservation lighting facilities on the basis of the respective state signals from said facilities to display the judgment result and reason.

CONSTITUTION: Signal input parts 1a-1n takes in the respective state signals from aerial preservation lighting facilities to supply the same to a data processing part 2. The processing part 2 converts the respective state signals to signals of a predetermined system to send the same to a judging part 4 and a state (signal position) display part 7. The judging part 4 performs inference processing on the basis of the respective state signals from the processing part 2 and the rule stored in an aerial preservation facility control and prescription rule base file part 3 to judge whether the aerial preservation lighting facilities correspond to aerial data items as a whole in a synthetic state and this judgment result is sent to an aerial data offering part 5 to be displayed and the judgment reason is also sent to a judgment reason display part 6 to be displayed. The display part 7 individually displays respective states on the basis of the respective state signals from the processing part 2. By this constitution, objective facilities can be more accurately monitored.