PURPOSE: To diagnose the abnormality without checking field facilities, by inputting the operating-stopping information and energy consuming information from the facility apparatus having rotating machines, and according to this information by diagnosing the abnormality of power transmission system of facility apparatus.

CONSTITUTION: A facility diagnosing device 10 has an input processing means 11, an output processing means 12, a facility operation diagnostic processing means 13 and an external information processing means 14. The result of external information processing is outputted into a display 20. A cable 31 transmits whether the facilities are in operation or not. Its information is taken in by the input processing means 11. A cable 32 transmits the energy consumption of facilities 50, whose consumption is also taken in by the input processing means 11. A cable 33 transmits the operating/ stopping signal from the facility diagnosing device 10 to the facilities 50.