Abstract: A dust-collecting electrostatic precipitator has a housing in which a multiplicity of collecting-electrode walls are provided in transversely spaced parallel relationship and defined between two gas channels. Each wall consists of a plurality of individual collecting-electrode strips whose side edges are hooked loosely into the side edges of adjacent strips so as to prevent relative rotation of the strips. At the top, all the strips of each collecting-electrode wall are secured to a common carrier while, at the bottom, the strips of each electrode wall are connected to a common rapping member or bar. The individual collecting-electrode strips are provided with spacers which are distributed over the height of the strip and project transversely therefrom, each spacer being anchored to one strip and extending across one of the gas channels to terminate just short of an opposing electrode strip while defining a gap therewith.