Abstract: A device for decreasing soot particles in exhaust gas, especially from an internal combustion engine, includes concentric outer and inner tubes forming an intermediate space through which the exhaust gas can flow. At least one annular electrode with a multiplicity of electrode tips protruding radially into the intermediate space is disposed on the inside of the outer tube. Terminals can connect the annular electrode and inner tube to a high voltage source forming an electric field in the intermediate space. At least two electrodes are preferably disposed axially at an electrode spacing of preferably 10 to 30 mm. The electrode tips can be approximately conical or pin-shaped with a radial length of 3 to 10 mm. The electrode tips of each electrode have a tip spacing in circumferential direction of 3 to 20 mm or 5 to 10 mm creating a very effective and uniform radial electric field for ionization.