The blood collection device (10) constituting the blood bag system (12) includes a hollow needle (80) that can penetrate the rubber stopper (202) of the blood collection tube (200) inserted into the blood collection holder (78), and a hollow needle. A hub (76) having a needle support portion (90) for supporting the proximal end side of (80) to which a blood collection holder (78) is rotatably mounted, and a state in which the distal end side of the hollow needle (80) is covered The rubber needle cover (82) externally fitted to the needle support portion (90) and the needle support portion (90) independently of the blood collection holder (78) in contact with the needle cover (82). And a cap (84) provided.血液バッグシステム（１２）を構成する採血器具（１０）は、採血ホルダー（７８）内に挿入される採血管（２００）のゴム栓（２０２）を貫通可能な中空針（８０）と、中空針（８０）の基端側を支持する針支持部（９０）を有して採血ホルダー（７８）が回転可能に装着されるハブ（７６）と、中空針（８０）の先端側を被覆した状態で針支持部（９０）に外嵌されたゴム製の針カバー（８２）と、針カバー（８２）に接触可能な状態で採血ホルダー（７８）とは独立して針支持部（９０）に設けられたキャップ（８４）とを備える。
