a first tube having one end to which a blood collecting needle is connected and the other end to which a blood bag is connected a second tube branched from the middle of the first tube through the branch section and a sealing member provided on the first tube at a portion located further toward the blood bag side than the branch section and, when broken, causing the first tube, which is in a shut-off state, to be in an open state. The second tube is communicated with the clamp, and the clamp is adapted to be able to be switched between a first state in which the second tube is open and operation for breaking the sealing member is prevented and a second state in which the second tube is closed and operation for breaking the sealing member is possible.