The outer cylinder (6) for a prefilled syringe comprises an outer tube body portion (61), a base end portion of the outer tube body portion (61) provided at a base end portion thereof, projecting outwardly and having an outer tube holding opening portion (61) enclosing the nozzle portion (64), the nozzle portion (64) provided at the tip portion of the outer tube body portion (61), the flange portion (62) And a lock adapter (70) having a diameter larger than the outer diameter of the outer cylinder holding member (4) and capable of passing through the outer cylinder holding opening portion (45), the outer cylinder for prefilled syringe (6) Is inserted from the distal end side into the tube holding opening (45), and the flange portion (62) comes into contact with the peripheral edge of the outer tube holding opening (45) and is suspended, and furthermore, the outer cylinder for the prefilled syringe (6) is located at the proximal end portion of the lock adapter (70) and is inclined toward the outer peripheral surface of the outer tube main body portion (61), and the outer cylinder for prefilled syringe from the outer tube holding opening portion (45) (70) for conducting guidance at the time of removal of the piston (6).プレフィルドシリンジ用外筒(6)は、外筒本体部(61)と、外筒本体部(61)の基端部に設けられ、外方に突出し、かつ外筒保持用開口部(45)を通過不能なフランジ部(62)と、外筒本体部(61)の先端部に設けられたノズル部(64)と、ノズル部(64)を被包し、かつ、外筒本体部(61)の外径より大径かつ外筒保持用開口部(45)を通過可能なロックアダプタ(70)とを備えており、プレフィルドシリンジ用外筒(6)は、外筒保持部材(4)の外筒保持用開口部(45)に先端側より挿入され、フランジ部(62)が外筒保持用開口部(45)周縁に当接し吊り下がった状態となっており、さらに、プレフィルドシリンジ用外筒(6)は、ロックアダプタ(70)の基端部に位置し、外筒本体部(61)の外周面に向かって傾斜し、外筒保持用開口部(45)からのプレフィルドシリンジ用外筒(6)の抜去時の誘導を行うための傾斜部(70)を有している。
