To prevent the occurrence of error and breakage of a flow meter and simplify the configuration of the device by providing a control valve for controlling the liquid flow and a reservation tank, etc., for temporarily accumulating a metered liquid.
This device is provided with a stock tank 3 for pooling a liquid 2, a bottom valve 4 for controlling the discharge of the liquid 2, a liquid flow meter 8, a reservation tank 12 for temporarily accumulating a metered liquid, etc. The input side of the meter 8 is prepared at the lower side in a gravity direction toward the outlet side of the valve 4, and the output side thereof at the upper side in a gravity direction toward the inlet side thereof, respectively. Therefore, an air within piping sections 5 and 7 can be discharged in the preparation stage, so that no error is generated during metering, resulting in improved metering accuracy. In addition, the flow meter can be prevented from breakage by discharging the air within the sections 5 and 7. Further, since the outlet side of a flow control valve 10 is directly connected with the outlet 12a of entering flow for the tank 12, a fluid can be led without exposing it in the air, and the inside of the tank 12 is thereby pushed up for appropriate accumulation.