The invention relates to an exhaust-gas aftertreatment device, comprising a control unit (4) for controlling a diaphragm pump (2) that draws a urea/water solution out of a circuit and pumps it, via a pressure filter (3), to a metering unit comprising an atomizing nozzle for atomizing the urea/water solution into an exhaust-gas stream.In advantageous developments, the metering unit comprises a metering valve, including an atomizing nozzle, a pressure and temperature sensor, a heating means and a return baffle.