PROBLEM TO BE SOLVED: To provide an indwelling needle capable of reducing deterioration of a valve element caused by the pressure of an elastic member.SOLUTION: A connector part 15 is mounted inside an outer needle body 12 in such a state as movable. The outer needle body 12 is connected to the base of a cannula 11, and has an internal space communicating with an inner lumen 11a of the cannula 11. The outer needle body 12 has the valve element 14 with an open/close hole 14a. The open/close hole 14a can make the inner lumen 11a of the cannula 11 and a channel of the connector part 15 communicate with each other when the distal end part of the connector part 15 is inserted liquid-tightly, and the open/close hole is closed when the distal end part of the connector part 15 is not inserted so that the front side is secluded from the rear side of the space of the outer needle body 12. In addition, a valve element presser plate 13 with an insertion hole 13a into which the distal end part of the connector part 15 can be inserted is disposed on the rear surface of the valve element 14, and a coil spring 16 is set between the valve element presser plate 13 and a spring socket 15c formed in the connector part 15.COPYRIGHT: (C)2008,JPO&INPIT【課題】 弾性部材の押圧による弁体の劣化を低減できる留置針を提供すること。【解決手段】 カニューレ11の基部に連結され内部にカニューレ11の内腔11aに連通する空間部が設けられた外針本体12の内部にコネクタ部15を移動可能な状態で設けた。そして、コネクタ部15の先端側部分を液密的に通してカニューレ11の内腔11aとコネクタ部15の流路とを連通させることができるとともにコネクタ部15の先端側部分が挿通していないときには閉塞して外針本体12の空間部の前部側と後部側とを遮断する開閉孔14aを備えた弁体14を、外針本体12内に設けた。さらに、コネクタ部15の先端側部分が挿通できる挿通穴13aを備えた弁体押さえ板13を弁体14の後面側に設け、弁体押さえ板13と、コネクタ部15に形成されたばね受け部15cとの間にコイルばね16を設置した。【選択図】 図4
