And to allow the liquid medicine to be injected when administered to the upper layer of skin a chemical solution to prevent leakage from the living body, allowing it to maintain a position that is Oshiki~tsu the pressing portion. A double-ended needle (3) having a needle tip 9 that can puncture a living body, the needle hub 4 for holding a double-ended needle 3, an outer cylinder 2, pre-filled syringe 1, the drug solution storage part 6 and the pressing portion 22, for accommodating a drug solution M and, Im provided with a holding portion 8, and a sealing member 23. The drug solution storage part 6 is arranged in the cylinder hole 2a of the outer cylinder 2. The pressing portion 22 is operated so as to be movable in the axial direction of the cylinder hole 2a of the outer tube 2 liquid medicine storage unit 6. Furthermore, the pressing state of being moved to the needle hub 4 side pressing portion 22 and the drug solution storage part 6 until discharging the chemical solution M, which is stored in the chemical storage unit 6, the holding portion 8 holding the pressing state of the pressing part 22 to.薬液を皮膚上層部に投与する際に注入する薬液が生体から漏れないように、押圧部を押し切った位置で保持することができるようにする。プレフィルドシリンジ1は、生体に穿刺可能な針先9を有する両頭針3と、両頭針3を保持する針ハブ4と、外筒2と、押圧部22と、薬液Mを収納する薬液収納部6と、保持部8と、封止体23とを備えている。そして、薬液収納部6は、外筒2の筒孔2a内に配置されている。また、押圧部22は、薬液収納部6を外筒2の筒孔2aの軸方向に移動可能に操作する。更に、保持部8は、薬液収納部6に収納された薬液Mを排出するまで薬液収納部6及び押圧部22を針ハブ4側に移動させた押圧状態において、押圧部22の押圧状態を保持する。
