A vacuum valve with a housing having a valve seat, a closure member which, in a closed position, is pressed against the valve seat, and a manual actuator, by which the closure member is displaceable in a linear manner and which includes a screw transmission, which is actuatable by a rotational element and has a first driving part connected to the rotational element and a second driving part connected to the closure member. The driving parts have mating external and internal threads. A closing spring acts between the valve housing and the closure member. The first driving part is displaceable relative to the valve housing parallel to the closing direction, and with the closure member in the open position, the closure member is held against displacement in the closing direction by a supporting stop against which a stop face of the rotational element or of the first driving part abuts.