PROBLEM TO BE SOLVED: To automatically discriminate existence and front/back of a blood cell filtration film in a blood filtration unit.SOLUTION: Ultraviolet light is applied from a light source 29 arranged on a position just above a blood filtration unit 11 to a storage chamber 18 in the blood filtration unit 11. Fluorescent light quantity in the storage chamber 18 is detected by a photodetector 30 arranged on the outside of the blood filtration unit 11. An inspection device 34 determines any one of NG (no filtration film), NG (back of a filtration film) and OK by comparing the fluorescent light quantity detected by the photodetector 30 with a low light quantity threshold Ta and a high light quantity threshold Tb predetermined as two steps. Thus the existence and front/back of a blood cell filtration film 16 in the blood filtration unit 11 can be automatically discriminated.
