Workpieces of carburizable materials, especially steels, are carburized by means of a pulsed plasma discharge in a carbon-containing atmosphere at pressures of 0.1-30 mbars and at pulsed voltages of 200-2,000 V, preferably of 300-1,000 V. A continuously applied baseline voltage, which is below the breakdown voltage, is superimposed on the pulsed voltage. The baseline voltage is preferably a direct-current voltage, which is in the range of 10-150 V, preferably of 20-100 V.