butterfly needle assembly (10) includes a needle body (16) and blade member (18) butterfly needle (12) and a, when moving relatively distal direction relative butterfly needle (12) , and a protector (14) in a state in which the wing member (18) is folded to cover the needle body (16). Wing element (18), the shaft portion fixed to the needle body (16) and (28), shaft portion (28) of an elastically deformable pair of extending in opposite directions wings (30a, 30b) and the a. Each of the pair of wings (30a, 30b) has its proximal side edge (36) is inclined so as to approach the shaft portion (28) side toward the proximal direction.翼状針組立体(10)は、針体(16)と翼部材(18)とを有する翼状針(12)と、翼状針(12)に対して相対的に先端方向に移動した際、翼部材(18)が折り畳まれた状態で針体(16)を覆うプロテクタ(14)とを備える。翼部材(18)は、針体(16)に固定された軸部(28)と、軸部(28)から互いに反対方向に延出した弾性変形可能な一対のウイング(30a、30b)とを有する。一対のウイング(30a、30b)の各々は、その基端側端縁(36)が、基端方向に向かうに従って軸部(28)側に近づくように傾斜する。
