This invention is a pen-type housing having a stomach tube and driven into the main chamber of the container 100, are used to keep the chemical liquid vessel in the abdominal portion in the main tube 200, the tube ends are set in the main volume of the chemical liquid metering vessel to be opened and closed bottom portion and a gate gwalyak chemical solution is combined with compressed cylinder weighing unit 300, linked to the driving part chemicals that are installed on top of the compression piston metering tube over an open interval and chemicals emitting portion pushes the exhaust out gwalyak gates weighing chemicals by advancing the piston within the metering tube when chemicals discharged 400, the drive cylinder is supported on the O-ring seal the compression spring is supported on the upper portion of the external force in the forward drive range, and by a piston driving unit installed in the intake pipe to the backward pressure of the spring to drive the piston for extruding liquid medicament (500), installed on the cylinder is closed at the open sections and connected to the gate that opens into the stomach of the vessel in extruded section to install the air supply and install an antibacterial filter intake passage in the intake passage by the chemicals in the container abdomen is filtered by the atmosphere when the negative pressure in the abdomen forced discharge of the vessel in the abdomen provides the chemical metering dropping vessel is provided for introducing the air introduction section configured (600). The invention in a metered volume of drug solution discharged by the pressure according to the chemical metering dropping vessel for discharging the metered volume of the drug solution in the container to the piston, and having a gate and gwalyak, chemical liquid is not exposed to the atmosphere nor suction back into the container, push release the button and the meter the chemical solution, the chemical release the negative pressure in the vessel
