Abstract: The invention relates to an electrostatic dust separator for horizontal gas throughflow, with a housing which is substantially rotationally symmetrical in relation to a central housing axis, with a tubular inlet port flaring in a single conical section up to 80 to 95% of the housing diameter, the remaining widening of 5 to 20% of the housing diameter taking the form of a step which is configured substantially perpendicularly and radially symmetrically in relation to the housing axis, with at least two perforated gas-distributing plates arranged in the conical section and substantially perpendicularly in relation to the housing axis.