A continuous-type filter made in the form of a cylindrical drum with filter cloth stretched over the convex surface of the drum. The drum rotates slowly about a horizontal axis, and the lower part is immersed in a tank containing the pulp to be filtered. Arrangement of pressure and suction pipes on the interior of the drum permits the application of suction to the filtering surface. As the filter passes through the tank, it picks up a layer of solid material and emerges carrying a layer of filter cake.