The 3rd bag where the blood bag system (30) collects the blood which remains behind inside the blood processing filter (8) which is substituted the 2nd bag which receives the processing blood which was processed the 1st bag which receives the blood which is supplied to the blood processing filter (8) and the blood processing filter (8) which process the blood by (1) and the blood processing filter (8) by retention liquid supply expedient (7) and the blood component retention liquid which supply the blood component retention liquid to (2) and the blood processing filter (8), receives the collection blood temporarily (3) and,2 bags (2) the blood component which is separated from the processing blood which is received inside is transported, the 4th bag which receives the blood component which was transported possesses (4).血液バッグシステム(30)は、血液を処理する血液処理フィルター(8)と、血液処理フィルター(8)に供給する血液を収納する第1バッグ(1)と、血液処理フィルター(8)によって処理された処理血液を収納する第2バッグ(2)と、血液処理フィルター(8)に血液成分保存液を供給する保存液供給手段(7)と、血液成分保存液によって置換された血液処理フィルター(8)内に残留する血液を回収し、回収血液を一時的に収納する第3バッグ(3)と、第2バッグ(2)内に収納された処理血液から分離された血液成分が移送され、移送された血液成分を収納する第4バッグ(4)とを有する。
