Abstract: The invention relates to a process for separating mercury out of flue gases from high-temperature plants, especially from power plants and waste incineration plants, in which reactants, for example in the form of bromine or alkali metal sulfides, are added to the flue gas beyond the firing operation in flow direction and then the flue gas is subjected to at least one dry cleaning operation for removal of the mercury and any excess reactants, wherein it is a feature of the process that the reactants and carbonaceous adsorbents in the form of activated carbons and/or activated cokes are introduced to the flue gas stream with separate metered addition, and the reactants are metered into the flue gas stream as a function of a preferably constantly measured mercury concentration.