- ADAPTER 5 A n adapter (20) is attached to an attachment part (4) which has a through - hole (9) and provided at a bottom part (7) of a blood sampling holder (3) which is a bottomed hollow cylinder. The adapter (20) includes: a hollow body part (21) which is connectable to a butterfly needle (40) for sampling blood from a human body and through which the sampled blood flows； a flange part (22) which is provided at a base end side of the body 10 part (21) and which abuts the leading end surface (8) of the attachment part (4)； and a cylindrical protruding part (23) which extend s from the flange part (22) in a direction opposite to the body part (21) and which is inserted into the through - hole (9) of the attachment part (4). In the outer periphery of the protruding part (23), a male screw part ( 27 ) is formed from the flange part (22) side, and a cut - out part (26) is formed by cutting 15 out a portion in a peripheral direction , closer to the base end side than the leading end side, of the male screw part (27). Figure 5A 20 25 30
