puncture device protector that is used by mounting (50) and (1) met Te, outer cylindrical body portion with the outer cylinder bore (4) is formed for accommodating the piercing device (50) and (3), the holding portion for holding the hub (52) and (5), the holder (5) an outer cylinder having extending portions extending in the proximal direction and (8) and (2) is held on the base end side of the barrel bore (4), inner tube lumen tube (53) is inserted ( 11) is formed, the outer cylinder bore (4) movable inner cylinder main body portion toward the distal end of (10), the distal end side of the inner diameter of the inner cylindrical body portion of the inner tube lumen (11) (10) towards and an inner cylinder (9) having a lumen inclined portion formed so as to gradually widens (12), by moving the inner tube (9) in the distal direction, the lumen inclined portion (12) the inner surface is in contact with the extension portion (8), extending portions (8) are energized by a tube (53) lumen inclined portion (12) in the direction in which the diameter.穿刺具(50)に装着して使用されるプロテクタ(1)であって、穿刺具(50)を収納する外筒内腔(4)が形成された外筒本体部(3)と、ハブ(52)を保持する保持部(5)と、保持部(5)から基端方向に延出する延出部(8)とを有する外筒(2)と、外筒内腔(4)の基端側に保持され、チューブ(53)が挿通する内筒内腔(11)が形成され、外筒内腔(4)の先端方向に移動可能な内筒本体部(10)と、内筒内腔(11)の内径が内筒本体部(10)の先端側に向って漸次拡がるように形成された内腔傾斜部(12)とを有する内筒(9)とを備え、内筒(9)を先端方向へ移動することによって、内腔傾斜部(12)の内面が延出部(8)に当接して、チューブ(53)が縮径する方向に内腔傾斜部(12)で延出部(8)が付勢される。
