A first connector (2) has a first connector main body configured from an outer tube (4) having a cylindrical shape, an inner tube having a cylindrical shape and a hub (12), a hollow needle (5) supported on the hub (12), a first sealing member supported on the inner tube, a coil spring (8) serving as puncturing portion biasing means for biasing the first sealing member in a direction toward the distal end thereof, and a clamping member disposed on the outer tube (4). The hub (12) is disposed at a proximal end portion of the outer tube (4). The hub (12) is disposed such that, although the hub (12) is initially connected to the outer tube (4) by a breakable welded portion (13), when the welded portion (13) is broken, the hub (12) is permitted to rotate around an axis of the outer tube (4) with respect to the outer tube (4).
