And double-ended needle having a proximal end and a needle tip and tip needle tip is attached to the mouth of the syringe, sealed liquid-tight mouth in that state, double-ended needle assembly as a medical instrument, Moto-tanhari destination a support member at has a piercing can piercing portion and movably supported along its axial direction a double-ended needle, is fixed to the double ended needle to cover the needle tip location in this state, the double-ended needle and a cover member to move operation, in the initial state, tip the needle tip is covered with the cover member, Moto-tanhari destination has become a non-penetrating state for piercing section, double-ended needle is, cover from the initial state In a state that has moved operations to the double-headed needle each proximal direction member, Moto-tanhari destination pierce piercing section, the cover member, fixed to the double-headed needle is released, double-ended needle is, and can be detached from the double-ended needle become.医療器具としての両頭針組立体は、先端針先と基端針先とを有する両頭針と、シリンジの口部に装着され、その状態で口部を液密に封止し、基端針先で刺通可能な刺通部を有し、両頭針をその軸方向に沿って移動可能に支持する支持部材と、両頭針に対し固定され、その状態で先端針先を覆うとともに、両頭針を移動操作するカバー部材とを備え、初期状態では、両頭針は、先端針先がカバー部材に覆われ、基端針先が刺通部に対し未刺通状態となっており、初期状態からカバー部材を両頭針ごと基端方向に移動操作した状態では、両頭針は、基端針先が刺通部を刺通し、カバー部材は、両頭針に対する固定が解除され、両頭針からの離脱が可能となる。
