The invention relates to a device (1) for the at least partial closing of an opening (2) of a room comprising a closing element (3) which is placeable sealingly on an opening bottom (1) and is guided vertically movable in guides (4), which are arranged vertically on both sides of the opening (2), between an open position in a upper area of the opening (2) and a closed position on the opening bottom (2) and which is connected to at least one counterweight (5), by means of which the closing element (3) is held motionless in its particular position without an additional force acting on the closing element (3).According to the invention, the closing element (3) is coupled to at least one pneumatic, hydraulic, and/or motor drive unit (8) for moving the closing element (3).