Medical container 1, and a proximal edge 25 which surrounds the mouth portion 21 and the proximal end opening 261 and the proximal opening 261, and the container body 2 liquid is possible and out through the mouth portion 21, mouth a plug 3 which seals the unit 21, the edge 41 is closely fixed to the base end edge portion 25 seals the proximal opening 261, surrounded by a rim 41, and a reversing section 42 for the inner and outer inverted a bag 4 having, and a space 12 surrounded by the container body 2 and the plug 3 and the bag 4, the inversion unit 42, with in and out the liquid into the space 12 through the mouth 21 By internal and external inverted, it can take a first state in which swells toward the front end side and a second state in which swells toward the proximal side. Medical container 1 comprises a loaded proximally mounted state so as to cover a proximal opening 261 into the container body 2, and a loaded tip side mounted state so as to cover the mouth portion 21 in the container main body 2 Toridoku , further I comprising a protective cover 6 which covers the bag body 4 of the second state in the base end side mounting state.医療用容器1は、口部21と基端開口部261と基端開口部261を囲む基端縁部25とを有し、口部21を介して液体が出入り可能な容器本体2と、口部21を封止する栓体3と、基端縁部25に密着固定されて基端開口部261を封止する縁部41と、縁部41に囲まれ、内外反転する反転部42とを有する袋体4と、容器本体2と栓体3と袋体4とで囲まれた空間12とを備え、反転部42は、口部21を介して空間12へ液体が出入りするのに伴って内外反転することにより、先端側に向かって膨らむ第1の状態と、基端側に向かって膨らむ第2の状態とを取り得る。医療用容器1は、容器本体2に基端開口部261を覆うように装着された基端側装着状態と、容器本体2に口部21を覆うように装着された先端側装着状態とを取り得、基端側装着状態で第2の状態の袋体4を覆う保護カバー6をさらに備える。
