This catheter assembly (10) comprises: a hollow catheter (12)； a catheter hub (14) that fixes and holds the catheter (12)； an inner needle (16) that has a needle tip (16a), and that is removably inserted through the interior of the catheter (12)； and a needle hub (18) that fixes and holds the inner needle (16). The catheter assembly (10) also comprises a catheter operating member (20) capable of operating the relative movement of the catheter (12) with respect to the inner needle (16). The catheter operating member (20) includes a holding part (58) that directly holds the catheter (12) in a detachable manner.
