PROBLEM TO BE SOLVED: To provide a multi-chamber vessel which is used for transfusions or the like and is configured to ensure the opening order of the multi-chamber vessel in which the initial opening of a weak seal section between partitioned chambers is followed by the opening of a weak seal section of a small vessel and to reliably prevent operation errors such as the transfusion only of a part of medicines.SOLUTION: The multi-chamber vessel includes an outer bag 10 and an inner bag 32. The outer bag 10 includes a weak seal section 28 as a first partitioning wall. The inside of the outer bag is partitioned by the weak seal section 28 into partitioned chambers 29 and 30 that house respective liquid medicines. The inner bag 32 has an outer periphery sealed by the weak seal section 38 and houses the medicine in the inside. All or a part of the weak seal section 38 also serves as a second partitioning wall that separates a lower side partitioned chamber 30 from a discharge control chamber 40. An external pressure that opens the weak seal section 38 of the inner bag 32 is set greater than an external pressure that opens the weak seal section 28 that separates the partitioned chambers 29 and 30. The weak seal section 28 is opened first, and subsequently, the inner bag 32 is opened by the external pressure on the liquid medicines housed in the outer bag 10.SELECTED DRAWING: Figure 1
