Closure device for vacuum closure of at least one opening (2) in a wall (1), comprising a valve plate (3) which is associated with a respective opening and which is displaceable between an open position in which it releases the opening, a position in which it covers the opening but is raised from the wall, and a closed position in which it covers the opening and contacts the wall, at least one
piston-cylinder unit (30) which serves to displace the valve plate (3) between its open position and its position in which it covers the opening (2) but is raised from the wall and which comprises a pneumatically actuated
piston (36) which is arranged in a cylinder housing (35) and which is outfitted with a
piston rod (29) leading out of the cylinder housing through a bore hole, at least one carrier unit (6) which is connected to the
piston rod (29) of the at least one piston-cylinder unit (30) and which is associated with a respective valve plate (3), has at least one cylinder bore hole (7) in which is arranged a pneumatically actuated piston (8) which serves to displace the valve plate (3) between its position in which it covers the opening (2) but is raised from the wall and its closed position and which is outfitted with a
piston rod (9) leading out of the carrier unit through a bore hole, the valve plate (3) being fastened to this
piston rod (9), wherein the at least one cylinder bore hole (7) of the at least one carrier unit is closed by a removable cover (11) and at least two sealing rings (15, 16) are arranged between the cover (11) and the carrier unit (6) and a line (17) which is connected to the
atmosphere or can be evacuated leads into the space enclosed by the two sealing rings (15, 16).