PCT No. PCT/SE87/00600 Sec. 371 Date Jun. 6, 1989 Sec. 102(e) Date Jun. 6, 1989 PCT Filed Dec. 14, 1987 PCT Pub. No. WO88/04570 PCT Pub. Date Jun. 30, 1988.A filter for separating particles from a flow of liquid comprises a filter drum (1) rotatably mounted about a substantially horizontal shaft and partially immersed into the filter liquid. The filter drum comprises a filter cloth (2) forming the circumference of the drum and having a plurality of radially extending sections between two drum end plates (3,4), one (3) of which is provided with a central opening through which the unfiltered liquid enters the interior of the drum. A drive means (9) rotates slowly. A belt conveyor (18) extends over the surface (23) of the liquid flow for removing the particles carried along by the filter cloth out of the liquid and falling down from the filter cloth in an area around the highest point of the drum. The filter cloth side edges formed as beads are clamped in grooves on the inside of the end plates (3,4), and the end plates (3,4) are fixed to each other by means of spacer members (D) spaced from the filter cloth.