A centrifuge (70) is provided with a cup (80) configured to house a blood bag system (10a) and centrifugally separates blood in the blood bag system (10a) by rotating the cup (80). The cup (80) has a segment holding section (86) capable of holding a plurality of segment tubes (44a), aligned in a parallel state by being folded at a sealing portion (44b) of an outlet-side tube (44), along a direction in which a centrifugal force acts during centrifugal processing or a direction inclined with respect to the direction in which the centrifugal force acts.
