Abstract: A filter device exhibits a chamber with a spiral which revolves helicoidally about the chamber axis. The spiral is constituted by a channel-shaped support which holds taut a filter constituted by a spiral-shaped tube. During the filtration of a suspension the liquid component of the suspension passes through the filter into the channel-shaped support and from the latter to a filtrate outlet. Because at least that part of the filter effective for the filtration forms a substantially smooth fold-free surface, uniform utilization of the total effective surface of the filter is possible. The solid residue deposited upon the surface of the filter can also be transported out of the chamber without difficulty by rotating the spiral.