Suction device to draw off sample liquids from filtration vessels to recipient vessels including an evacuable chamber, which has an upper opening with a continues circular sealing surface for marginally supporting at least one filtration vessel mountable in place from top and may be opened for the insertion and removal of at least one recipient vessel, and including a support parallel to the sealing surface to enable the recipient vessel to be positioned in the chamber below the filtration vessel wherein the upper opening including the circular sealing surface is disposed on a first chamber portion adapted to be displaced with regard to a stationarily disposed, second chamber portion including the support where the first and second chamber portions complement each other in a charging position to form a sealed chamber and the first chamber portion releases the support, in an access position displaced away from the second chamber portion, for the insertion and removal of the recipient vessel.