As for the detention needle assembly body, while possessing ahead the sharp needle in the Tip, while being locked to the basic destal of the needle and the needle inside the said, the needle hub and the inside needle the Interpolation outside is locked to the basic destal of the outside needle of the air which passes and the needle outside the said in the needle hub and the inside needle hub the Interpolation sequence, at the same time, in order in the basic destal of the outside needle hub, for lumen to communicate with the lumen of the outside needle, when possesses with the tube which is jointed, the inside needle the Interpolation it passes in the outside needle, the medial axis in the Tip of the medial axis and the tube of the outside needle almostIn order to become parallel, it is constituted.留置針組立体は、先端に鋭利な針先を有する内針と、該内針の基端部に固定された内針ハブと、内針が挿通される中空の外針と、該外針の基端部に固定された外針ハブと、内針ハブに挿通され、かつ、外針ハブの基端部に、内腔が外針の内腔と連通するように接続されたチューブとを有し、内針を外針に挿通した状態で、外針の中心軸とチューブの先端部における中心軸とがほぼ平行となるように構成されている。
