PURPOSE: To measure the temperature and level of oil and to calculate its necessary feeding volume automatically by forming a temperature calculating means obtained by fitting plural temperature detectors to a measuring device body, an oil level calculating means and a necessary feeding volume calculating means.

CONSTITUTION: The measuring device body 8 is attachably/detachably fitted to an oil storing body and plural thermocouples 7 which are temperature detectors for detecting the temperature of oil are fitted to the body 8 in its longitudinal direction with prescribed intervals. Respective thermocouples 7 are connected to an arithmetic unit 14 through electric wires 9 penetrated into a cap 6. The arithmetic unit 14 is provided with the temperature calculating means 11 for calculating the temperature of the oil on the basis of signals outputted from the thermocouples 7, the level calculating means 12 for calculating a position where the temperature difference of oil based upon the adjacent thermocouples 7 is maximized and the necessary feeding volume calculating means 13 for calculating the volume of oil to be supplied on the basis of the temperature of the oil and the calculated volume of oil. The information calculated by the calculating means 13 is displayed on a display device 18 to feed oil manually or automatically.