A catheter assembly (10) includes: a hollow catheter (12)； a catheter hub (14) adapted to fix and hold the catheter (12)； an inner needle (16) inserted into the catheter (12)； and a needle hub (18) adapted to fix and hold the inner needle (16), and a catheter operation member (20) capable of controlling movement of the catheter (12). Additionally, a support member (44) is provided at the needle hub (18) and the support member (44) includes a support main body portion (102) freely movable to a first position (P1) capable of contacting and supporting the catheter (12) and a second position (P2) that is a different position from the first position (P1) and not contacting the catheter (12).
