<p>An automatic stop valve mounted in a liquid supply port of a container to be supplied with pressurized liquid, which valve ensures that liquid supply is automatically and instantaneously stopped when the liquid surface reaches a predetermined level. The valve comprises a hollow valve body with at least one liquid supply port formed at one end and one or more liquid discharge ports formed in the vicinity of the other end, a valve cylinder loosely engaged with the valve body and adapted to be movable axially of the valve body as the level of the pressurized liquid supplied into the container rises and a valve release mechanism for opening the valve by pressing the valve cylinder downwardly. The valve body has a pair of axially spaced seal members secured on the periphery of the valve body with the liquid discharge ports positioned between the seal members, and wherein the valve cylinder may contact the seal members liquid-tightly at both axial ends when the liquid level reaches a predetermined level.</p>
