Method and device for discharging a fixed amount of liquid

A method for discharging a fixed amount of liquid, comprising:

• providing an apparatus that comprises a first pressure reducing valve for decompressing a compressed gas supplied from a pressure gas source, a discharge valve for controlling a passage amount of the gas decompressed by the first pressure reducing valve, a liquid reservoir for discharging the liquid through a nozzle by pressing the liquid with the gas supplied through the discharge valve, and a buffer tank disposed between the first pressure reducing valve and the discharge valve and having a larger volume than the liquid reservoir,
• setting flow resistance of a flow path communicating the buffer tank and the liquid reservoir larger than flow resistance of a flow path communicating the buffer tank and the first pressure reducing valve, thereby suppressing a pressure reduction that is generated in a flow path, through which the compressed gas is supplied to the liquid reservoir, when the first pressure reducing valve is operated.