Büchner funnel is a piece of laboratory equipment used in filtration. It is traditionally made of porcelain, but these days plastic funnels are also available. On top of the funnel-shaped part there is a cylinder with a perforated plate separating it from the funnel. The filtration material, often filter paper, is placed on the plate. The liquid to be filtered is poured into the cylinder and drawn through the perforated plate by vacuum suction.