PROBLEM TO BE SOLVED: To provide a port attached to a bag main body for accommodating a chemical solution to more surely prevent a sealing plug from falling off from the port main body. SOLUTION: A port 3 has a sealing plug 30 capable of penetrating a hollow needle N, a hollow port main body 31 in which the sealing plug 30 is arranged, and a retaining member 32 attached to the port main body 31. The port body 31 has a tubular sealed portion 310 in which the sealing plug 30 is sealed, and a fitted portion 312 formed in the sealed portion 310, and is a retaining member. Reference numeral 32 denotes a main body portion having a first surface facing the first end side of the sealed portion 310 in the sealed portion 310, and a regulating portion 321 formed on the first surface of the main body portion. It has a regulating portion 321 that regulates the movement of the sealed portion 310 to the second end side of the sealing plug 30, and a fitting portion that fits into the fitted portion 312 of the port body 31. [Selection diagram] FIG. 8【課題】薬液を収容するバッグ本体に取り付けられるポートにて封止栓がポート本体から脱落することをより確実に防止するポートを提供する。【解決手段】ポート３は、中空針Nを刺通可能な封止栓３０と、該封止栓３０が内部に配置される中空のポート本体３１と、該ポート本体３１に取り付けられる抜止部材３２とを備え、ポート本体３１は、該封止栓３０が封入される筒状の被封止部３１０と、該被封止部３１０に形成される被嵌合部３１２とを有し、抜止部材３２は、被封止部３１０内で該被封止部３１０の第一端側に向く第一面を有する本体部と、該本体部の第一面上に形成された規制部３２１であって、封止栓３０における被封止部３１０の第二端側への移動を規制する規制部３２１と、ポート本体３１の被嵌合部３１２に嵌合する嵌合部とを有する。【選択図】図８
