Installation and removal being installed by the stab instrument itself possibly, the stab needle cartridge 20 which forms the stab instrument, the needle itself which possesses stab section 212a it accommodates 21 and needle itself 21 and it has with the casing 22 which possesses the respective opening 223,224 in the front and the rear of needle itself 21, the needle itself where needle itself 21 is arranged, the evacuation position which point 212c of the stab section evacuates inside casing 22 and receiving pushing pressure from the stab instrument, itself the projection position to which point 212c of the stab section from casing 22 projects to outside direction with, advance and retreat possibly, is projection position 21The energization expedient which energization is done is had for evacuation position. This stab needle cartridge at cost is superior low in potential for mass production, the user can do the stab safely and simply.穿刺器具本体に着脱可能に装着されて穿刺器具を構成する穿刺針カートリッジ20であって、穿刺部212aを有する針本体21と、針本体21を収容し針本体21の前方および後方にそれぞれ開口223,224を有するケーシング22とを備え、針本体21は、穿刺部の先端212cがケーシング22内に退避した退避位置と、穿刺器具本体から押圧力を受けて穿刺部の先端212cがケーシング22から外方に突出する突出位置との間で、進退可能に配置されており、突出位置にある針本体21を退避位置に付勢する付勢手段を備える。この穿刺針カートリッジは、低コストで量産性に優れ、使用者が安全かつ簡便に穿刺することができる。
