To provide a dual-chamber type container/syringe 1 capable of combining the dispersibility of a liquid agent, the strength of an outer cylinder 100, and the handling property.SOLUTION: In the dual-chamber type container/syringe, the ratio of the radial thickness of a bypass section 120 to the radial thickness of an outer cylinder body 110 is 0.8 to 1.0. The radial position of the outer surface 121a of the bypass section 120 is located at a position radially outward of the outer peripheral surface 110a of the outer cylinder body 110. The radial position of the inner surface 121b of the bypass section 120 is between the inner peripheral surface 110b and the outer peripheral surface 110a of the outer cylinder body 110.SELECTED DRAWING: Figure 2【課題】液剤の分散性、外筒１００の強度及び取り扱い性を両立させることができる二室式容器兼用注射器１を提供する。【解決手段】二室式容器兼用注射器において、外筒本体１１０の径方向の厚さに対するバイパス部１２０の径方向の厚さの比が、０．８～１．０とされ、バイパス部１２０の外面１２１ａの径方向位置が、外筒本体１１０の外周面１１０ａよりも径方向外側とされ、バイパス部１２０の内面１２１ｂの径方向位置が、外筒本体１１０の内周面１１０ｂと外周面１１０ａとの間とされている。【選択図】図２
