Abstract: A stop cock for a liquid container, comprising a substantially annular valve housing, a circular valve rotatably mounted in the valve housing, a handle mounted on an operational shaft for rotating the valve between a closed and open position, a seat mounted in the valve housing and cooperating with the valve in the closed position, characterized in that the handle (21) comprises a recess (28) for rotatably receiving a stop bush (29) that comprises a cam (30) which in the closed position cooperates with an indentation (42) of a top plate (24) arranged on a boss (9) and includes a circular passage for shaft (7), said stop bush (29) having an unround passage (33) for mounting a correspondingly formed driving shaft (34) of an unlocking lever (35), the handle (21) and the top plate (24) in a plurality of positions.