A puncture device according to an embodiment of the present disclosure includes a tubular needle member having a deformable flexible portion, and a regulation position that regulates the deformation of the flexible portion on the outer side in the radial direction of the needle member with respect to the flexible portion. And a puncture aid that is movable or deformable in the axial direction of the needle member between the flexible part and an allowable position that is not located outside in the radial direction and that allows deformation of the flexible part. The member, wherein the puncture assisting member moves or deforms from the restricted position to the allowed position in conjunction with the operation of inserting the flexible portion into the living body when the needle member is punctured.本開示に係る穿刺装置は、変形可能な可撓部を備える管状の針部材と、前記可撓部に対して前記針部材の径方向の外側で、前記可撓部の変形を規制する規制位置、及び、前記可撓部に対して前記径方向の外側に位置せず、前記可撓部の変形を許容する許容位置、の間で、前記針部材の軸方向に移動又は変形可能な穿刺補助部材と、を備え、前記穿刺補助部材は、前記針部材の穿刺時に、前記可撓部が生体内に挿入される動作と連動して、前記規制位置から前記許容位置へと移動又は変形する。
