A cleaning apparatus for removing synthetic residues from rotating parts of plastics processing machines includes a heatable tubular container which contains a dry powder or granular filling and is provided with an upper axial opening through which the part to be cleaned is introduced into the container. The part is clamped at its one end by a chuck which cooperates with a double-acting piston/cylinder unit so as to be movable upwardly and downwardly for introducing the part to be cleaned in the container and removing it therefrom after the cleaning cycle.