A catheter assembly includes a catheter, a catheter hub, an inner needle, and an inner needle hub. The catheter assembly is disposed in a hollow portion axially extending in the interior of the inner needle, and includes a blunt needle having a distal end portion blunter than a needle tip and a movement mechanism for moving the blunt needle. The movement mechanism is configured separately from the catheter hub and causes the distal end of the blunt needle to protrude beyond the needle tip along with the movement of the catheter.