When a hub (40) is in an initial position at which it is located on the front end side of an inner cavity of a shield (20), an inner needle (50) penetrates an outer needle (30) and protrudes from a leading end of the outer needle to the outside, and when the hub is in a retracted position at which it is located on the rear end side of the inner cavity of the shield, the inner needle is housed within the inner cavity of the shield. A first side hole (31) is formed in an outer circumferential face of the outer needle, and a second side hole (51) is formed in an outer circumferential face of the inner needle. When the hub is in the initial position, an inner circumferential face of a region (33) of the outer needle that contains the first side hole is in close contact with the outer circumferential face of the inner needle, and the second side hole is located closer to the hub than the region where the inner circumferential face of the outer needle is in close contact with the outer circumferential face of the inner needle. Thus, a priming operation for filling a gap between the inner needle and the outer needle with blood can be easily performed, and leakage of blood through the side hole of the outer needle during puncture does not occur.
