A vessel for regenerating used catalyst comprising at least one combustion zone provided with at least two walls (5a, 5b) between which the catalyst circulates as a moving bed, and provided with at least one conduit (4) for introducing at least one oxygen-containing gas entering the moving bed via one of the walls and leaving via another wall, characterized in that it also comprises a zone (FC) for monitoring and controlling the end of combustion located after the end of the flame front of the last combustion zone (Z2), provided with a conduit (11) for introducing an oxygen-containing monitoring and control gas and at least one means for measuring the temperature and/or the oxygen content in the gas and/or the catalyst leaving the monitoring and control zone.A separator (29) is located between the monitoring and control zone and the last combustion zone for preventing the passage of gas while allowing for the passage of the catalyst.