PROBLEM TO BE SOLVED: To provide a catheter assembly which is easy to operate and which can effectively suppress bending of an inner needle at the time of puncturing. A catheter assembly (10B) includes a protector (90) that connects a catheter hub (84) and a needle hub (88), a needle support portion (20) that supports an inner needle (86) via a catheter (82) on the tip side of the catheter hub (84), and a catheter. And a hub operating section for operating the hub 84. The needle support portion 20 includes a pair of support arms 42 that can be opened and closed in the left-right direction, and a restraint portion 44 that can restrain the pair of support arms 42 in a closed state and can release the restraint. When the hub operating portion advances, the restraint on the pair of support arms 42 is released, and the protector 90 covers the needle tip of the inner needle 86. [Selection diagram] Fig. 13【課題】操作が容易であるとともに、穿刺時の内針の撓みを効果的に抑制することができるカテーテル組立体を提供する。【解決手段】カテーテル組立体１０Ｂは、カテーテルハブ８４と針ハブ８８を接続するプロテクタ９０と、カテーテルハブ８４よりも先端側でカテーテル８２を介して内針８６を支持する針支持部２０と、カテーテルハブ８４を操作するためのハブ操作部とを備える。針支持部２０は、左右方向に開閉可能な一対の支持アーム４２と、一対の支持アーム４２を閉じた状態に拘束可能であり且つ拘束を解除可能な拘束部４４とを有する。ハブ操作部の前進時に、一対の支持アーム４２に対する拘束が解除されると共に、プロテクタ９０が内針８６の針先を覆う。【選択図】図１３
