Abstract: A method of and installation for incineration of solid and, if desired, liquid waste. The installation comprises a pyrolysis chamber and connected directly therebelow a combustion chamber. Exhaust gas ducts which cover the outer walls of the pyrolysis chamber either partly or completely in such a way that the covered wall surfaces of the pyrolysis chamber serve as the inner walls of the exhaust gas ducts. One or more swivelling gate elements which when moved create passages of different cross-sections through which solid and gaseous products from the pyrolysis process are discharged from the pyrolysis chamber into the combustion chamber. Combustion air supply inlets are arranged in flow direction behind the gate elements.