The stab needle assembly body, the protector and the protector which are moved with to the 1st position which covers ahead the needle of the needle tube and the needle tube and the 2nd position which the tip of the needle exposes has with the substance section which has the support section and the elastic deformation section which movement possibly are supported and the protector and the 1st engagement section and the elastic deformation section and the engagement possible 2nd engagement section has the portable regulation component which is engaged, the occasion which the protector moves to 2nd position from 1st position and for the second time moves to 1st position, the 1st engagement sectionThrough, every portable regulation component which is engaged moving, when it tries, that the protector of 1st position will move to 2nd position, reaching up to 1st position, the portable regulation component this touches to the protector, regulates the movement of the protector due to the fact that at the same time the 2nd engagement section engages in the elastic deformation section.穿刺針組立体は、針管と、針管の針先を覆う第1の位置と針先が露出する第2の位置とに移動するプロテクタと、プロテクタを移動可能に支持する支持部と弾性変形部とを備える本体部と、プロテクタと係合する第1の係合部と弾性変形部と係合可能な第2の係合部とを備える移動規制部材とを有し、プロテクタが第1の位置から第2の位置に移動して再度第1の位置に移動する際に、第1の係合部を介して係合された移動規制部材ごと移動して第1の位置に至り、第1の位置のプロテクタが第2の位置に移動しようとすると、移動規制部材は、プロテクタに当接し、かつ第2の係合部が弾性変形部に係合することによって、プロテクタの移動を規制する。
