A catheter assembly includes a catheter, a catheter hub fixed to a proximal end portion of the catheter, a hollow inner needle detachably inserted in to the catheter, a pressing member configured to press a portion between a proximal end and a distal end of the catheter, a guide wire slidably inserted into the inner needle, and a wire operating member which is configured to be displaced in a longitudinal direction relative to the inner needle and the catheter and is connected to the guide wire.
