Abstract: The invention relates to a method for processing waste or biomass material into valuable products such as, for example, combustible gases, which is characterized in that(a) the waste or biomass material is subjected to a pyrolysis at a temperature of 350-650.degree. C., advantageously 450-550.degree. C.;(b) the gas released in the course of the pyrolysis is subjected--without condensation--to a cracking treatment at a temperature of 1100-1600.degree. C., advantageously 1200-1400.degree. C., under the influence of oxygen-rich gas introduced from outside and possibly of steam;(c) the residue liberated in the course of the pyrolysis is gasified under a pressure of 0.5-1.5 bar, advantageously 0.8-1.2 bar, at a temperature of 1200-1700.degree. C., advantageously 1400-1600.degree. C.