A multistage gas washing system is applied for dust separation from crude gases of entrained flow gasification of pulverized fuels under pressures up to 10 MPa and temperatures which are greater than the melting point of the fuel ash. A first stage comprises a modified quenching system and a downstream washing column, which operates as a bubble column. A second washing stage comprises one or more Venturi washers connected in series. A third washing stage comprises multiple high-pressure atomization units of washing water, a partial condenser for cooling the crude gas by 1 to 15° C. with condensate formation, and a separation column, which is equipped with washing surfaces and a plastic-coated demister.