A method of performing a diagnosis of an exhaust gas sensor disposed in an exhaust gas region of an internal combustion engine testing the sensor to determine whether a change of at least one exhaust gas component, which is detectable by the exhaust gas sensor, results in an expected change of the sensor signal, and implementing the diagnosis if a specified change in at least one operating parameter of the internal combustion engine and/or at least one parameter of the exhaust gas in the running operation of the internal combustion engine are detected.