A catheter assembly is provided with a catheter, a catheter hub, and a valve body (medical valve) provided in the catheter hub. The valve body includes a hollow main body provided with a distal end surface and a fixing portion for fixing the valve body to the catheter hub. At least a part of an outer peripheral surface and at least a part of an inner peripheral surface of the main body are inclined with respect to a central axis of the valve body. The main body of the valve body includes a distal end slit provided on the distal end surface and a side slit provided on the outer peripheral surface of the main body and continuously extending from the distal end slit.
