The invention relates to the collector stage of an electrostatic precipitator for cleaning flue gas produced during combustion processes, consisting of a collector stage (2) comprising at least one collector pipe (3) in which a spiral brush (5) is rotationally mounted. The brush consists of a central rod or pipe (4) which extends coaxially to the collector pipe and consists of sections which are arranged to be rotationally offset to one another. The brush wires on the rod or pipe segments protrude radially relative to the spiral axis and touch the inner wall of the collector pipe with their free end in such a manner that deposited particles on the inner wall of the collector pipe are brushed away when the brush turns. The collector pipe and the brush lie on a common electrical reference potential and can therefore act as a precipitation surface. The offset arrangement of the brush axis increases the efficiency of the particle precipitation.