Abstract: A method for processing of plastic and/or rubber waste to generate energetic gas comprising aliphatic hydrocarbons C1-C4, carbon oxide and hydrogen, wherein the waste may comprise halogens, sulphur, nitrogen and oxygen and may be contaminated by substances of inorganic origin comprising ceramic and metallic materials, the method comprising processing the waste in a pyrolysis process, wherein a powdered waste material is fed to a microwave drum reactor (102), where it is heated by microwaves while being moved through the reactor (102), the method comprising: conducting the pyrolysis reaction inside the reactor (102) at a temperature of 800-950° C.