In a process for the control of charging and discharging of an oxygen reservoir (4) of an exhaust gas catalytic converter (3) as a function of the voltage signal (ULSF) of a binary lambda probe (5) mounted downstream from the exhaust gas catalytic converter (3), it is proposed that according to the differentiation of the case the voltage signal (ULSF) which has been output by the lambda probe (5) mounted downstream from the exhaust gas catalytic converter (3) is divided into three regions (A, B, C) which each trigger different control strategies for charging and discharging of the oxygen reservoir (4) of the exhaust gas catalytic converter (3). As proposed, economical binary lambda probes (5) can be used for favorable control of charging and discharging of the oxygen reservoir (4) in order to set or maintain the setpoint region of mean charging of the oxygen reservoir (4) from approximately 30 to 70% which is optimum for conversion of the exhaust emissions.