While ensuring technical safety and a short start-up time the invention permits the operation of autothermic partial oxidation of fuels processed into pulverized fuel such as lignite and bituminous coals, petroleum cokes, solid grindable carbon-containing residues, as well as solid-liquid suspensions or slurries, with a gasification agent containing oxygen at operating pressures of up to 8 MPa (80 bar). The selective configuration of the fail-safe monitoring of the gasification process only the supply of the main fuel is cut off. Through the continued operation of the pilot and ignition burner the reactor is kept at operating pressure and after the fault has been rectified fuel gasification can be restarted with the pilot and ignition burner without a complicated placement and pulling of a starter burner and subsequent pressurization of the reactors.