A medical bag comprising: a bag main body comprising a flexible sheet material having an interior portion partitioned via a partition part into a first space and a second space that is smaller than the first space, a first liquid housed in the first space, and a second liquid housed in the second space. When the volume of the first liquid is set as L1 and the volume of the second liquid is set as L2, L1/L2 is 2.0 to 6.0. The partition part has a breaking strength of 5 to 25 kPa.
