As for this invention, in regard to the detention needle and its production method, as for the detention needle (10), it has with the internal pipe (22) which is provided with the catheter (20) and the stab needle (18) and the catheter (20) which consist of the resin lumbering charge which is provided on peripheral side of the stab needle (18) and the stab needle (18) which consist of the rod (44) of air, on the inside perimeter aspect of the catheter (20), extending the helical concave groove (30) which is present is formed as according to the axis direction of the catheter (20), the inside perimeter aspect of the catheter (20)With it can provide the gap (32) of specified interval with the peripheral aspects of the internal pipe (22). This concave groove (30) as it is formed to the section semicircle condition which becomes depressed in convex condition facing toward peripheral side of the catheter (20), with the internal pipes (22) is kept in airtightness.本発明は、留置針及びその製造方法に関し、留置針(10)は、中空の管状体(44)からなる穿刺針(18)と、穿刺針(18)の外周側に設けられる樹脂製材料からなるカテーテル(20)と、穿刺針(18)とカテーテル(20)との間に設けられる内管(22)とを備え、カテーテル(20)の内周面には、カテーテル(20)の軸線方向に沿って延在する螺旋状の凹溝(30)が形成されると共に、カテーテル(20)の内周面と内管(22)の外周面との間に所定間隔の間隙(32)が設けられる。この凹溝(30)は、カテーテル(20)の外周側に向かって凸状に窪んだ断面半円状に形成されると共に、内管(22)との間で気密に保持される。
