The invention pertains to a process for combusting coke of a coke-containing FCC catalyst in a regeneration unit of a FCC unit having the introduction of oxygen-containing gas through a gas-transport unit into the regeneration unit and combusting the coke by means of an oxygen-containing gas, in which the oxygen-containing gas is cooled in a cooling unit before it is brought in contact with the coke-containing FCC catalyst. The invention further relates to an apparatus for performing said process.