Abstract: An apparatus for separating particulate or powdery material from an entraining gas includes a housing defining a closed chamber having an inlet for the material and gas, an outlet in the lower region of the housing for separated material, an outlet for filtered gas and a tubular filter disposed between the inlet and gas outlet and mounted such that the gas must pass through the filter to reach the gas outlet. A first washing device is provided for introducing a washing liquid into the chamber and washing the interior of the housing and the filter, and a second washing device is disposed in an upper region of the filter and includes nozzles connected to the end of a liquid supply pipe which extends coaxially or concentrically within a back flow gas supply pipe.