SYRINGE

Disclosed is a syringe. The disclosed syringe is a syringe inhaling and discharging an injection liquid by reciprocating a piston included in a cylinder. The syringe includes a connecting cap combined with the front end of the cylinder and having an inhaling path and a discharging path connected to the cylinder; a filter block assembled at the front side of the connecting cap, including a through hole selectively connected to the inhaling and discharging paths, and including a spiral groove on the outer surface; a filter inserted into the front surface of the connecting cap and letting the injection liquid pass without filtering by a hole formed at the same position as the inhaling path′s; a pad placed on the front surface of the filter and including a hole connected to the through hole of the filter block; and a needle holder including a syringe needle in the front, making the filter block and the connecting cap sequentially inserted by first and second installation holes in the inside, and inserted into the spiral groove by including a pressurizing rib in the first installation hole. The injection liquid flows into the cylinder through the syringe needle, the through hole, and the inhaling path. When the injection liquid is discharged according to medication, the pressurizing rib moves along the spiral groove by moving linearly the needle holder while the filter holder rotates to inject through the discharging path, the filter, and the through hole.