PROBLEM TO BE SOLVED: To provide a blood component collector capable of reducing time required for collection of blood components. SOLUTION: The blood component collector carries out a blood component collection process to centrifugally separate blood collected from a blood donor and collect a blood component (plasma) and a blood component return process to return blood in the centrifugal separator. In the blood component collection process, a first collection quantity X1 is constantly detected, and the hematocrit value Hct1 of blood in a centrifugal bowl is obtained on the basis of the first collection quantity X1 , the hematocrit value Hct2 of the blood of a blood provider, and the volume V1 of blood in the centrifugal bowl (S105), and when the hematocrit value Hct1 of blood in the centrifugal bowl reaches the target hematocrit value previously set (S106), the blood component collection process is ended and the blood component return process is initiated.
