PURPOSE: To provide a feed oil device by which the measuring deviation of flow rate meters can be checked automatically by necessary times in both large and small flow rates.

CONSTITUTION: An oil sucked by a pump 12 is supplied from a feed oil nozzle 17 through a flow rate meter 14, a feed oil pipe 15, and a feed oil hose 16 and the oil quantity measured by the flow rate meter 14 is shown on an indicator 20 in a feed oil device. A changeover throttle valve 31 to either a large flow rate or a small flow rate set in the feed oil pipe 15 at the downstream side of the flow rate meter 14 is connected to branch pipes 37, 38 which can be changed over to the feed oil pipe 15 through three-way valves 32, 33. And the device is also provided with a testing flow rate meter 35 set between the branch pipes 37, 38 and a branch pipe 39 returning the oil flowing in the testing flow rate meter 35 to the upstream side of the pump 12. The throttle valve 31 is changed over either a large flow rate or a small flow rate and the oil quantity measured by the flow rate meter 14 and the oil quantity measured by the testing flow rate meter 35 are compared respectively and the compared result is displayed on the indicator.