To provide a blood storage tank, in which damage to stored blood in reduced.

This blood storage tank 1' is provided with a box-shaped housing 2 and filtering and antifoaming devices 7b, 7c, and 7d respectively set inside the housing 2. The blood drawn from the main vein flows in to the filtering and antifoaming device 7b from a blood inflow port 5c, vent blood sucked from the heart flows in to the filtering and antifoaming device 7c from a blood inflow port 5a and sucked blood sucked from an operation field (other than the heart) flows in to the filtering and antifoaming device 7d from a blood inflow port 5b. The filter member 27 of the filtering and antifoaming device 7d filters foreign matters from the sucked blood. The vent blood passes through the filter member 22 of the filtering and antifoaming device 7c and enters a blood storage space 25 without being in contact with the foreign matters filtered from the sucked blood.