Drug injection device

A drug injection device comprising:

• a gun-type housing configured to include a grip part, an operation part adjacent to the grip part, and a mounting part located above the grip part, and to have an interior space that is spatially connectable with a suction device;
• a syringe placed on the mounting part;
• a drug injector mounted on an edge of the mounting part, configured to supply a drug by communicating with the syringe, provided with a flow path spatially connected to the interior space of the gun-type housing, and configured to quantitatively inject a drug by improving adhesion to skin due to a vacuum generation part provided between the skin and a front surface thereof by an operation of the suction device;
• a suction connection part disposed at an edge of the gun-type housing and spatially connectable with the suction device;
• and
• an air filtering unit disposed in the gun-type housing and configured to have at least a portion thereof spatially connected to the flow path to filter suction air in the interior space.