Abstract: The present invention relates to a process consists of the hydrolytic decomposition of the polychlorinated hydrocarbons: of polychlorinated aliphatics and especially of polychlorinated aromatics and oxidizing the chlorine-free product at elevated temperature in the presence of a carrier gas in one unit characterized by a hot and a transitional temperature zone, whereby the calcium chloride and the exiting gas mixture are removed continuously and the excess heat of the highly exothermic process is utilized. The present invention also relates to an apparatus for the process which is carried out in an Apparatus of FIG. 1.