A method removes combustion residues from a wall of a chamber which carries combustion gases and/or from at least one component which is disposed in the chamber. The method includes making contact between the combustion residues and a first cleaning medium, and making contact between the pretreated combustion residues and a second cleaning medium. The first cleaning medium and the second cleaning medium differ at least with regard to a physical state. An apparatus for removing the combustion residues has different cleaning appliances and operating areas which at least partially overlap. The method and the apparatus allow, for example, heat exchanging surfaces in steam generators to be cleaned in a particular careful and thorough manner.