Method for operating a gas sensor, the gas sensor comprising a set of gas sensing cells having the same gas detecting properties, each gas sensing cell comprising on or integrated in a substrate a gas sensitive element , a set of electrodes , a heater for heating the assigned gas sensitive element, and a control unit for controlling the heaters of the individual gas sensing cells and performing the method steps below, the method comprising - during a first period (T1) in the lifetime of the gas sensor conducting gas measurements with a first gas sensing cell (FSC) of the set by activating the corresponding heater to heat the assigned sensitive element , while at the same time leaving the heater of another gas sensing cell (OSC) of the set inactive or activating this heater solely for conducting a reference gas measurement at a rate less than the conducting of gas measurements by the first gas sensing cell, - in response to a trigger (TR1), conducting gas measurements during a second period (T2) in the lifetime of the gas sensor following the first period (T1) with the other gas sensing cell (OSC) by activating the corresponding heater to heat the assigned sensitive element , while at the same time leaving the heater of the first gas sensing cell (FSC) inactive or activating this heater solely for conducting a recovery gas measurement at a rate less than the conducting gas measurements by the other gas sensing cell, wherein the conducting of a gas measurement includes measuring an electrical resistance (R11) of the subject gas sensing cell during activating or after having activated the corresponding heater , and wherein the trigger (TR1) is generated by the control unit dependent on one or more of a value of the electrical resistance (R1) measured and a change in the measured electrical resistance value (ΔR1) exceeding an assigned threshold in response to activating the heater . - during a first period (T1) in the lifetime of the gas sensor conducting gas measurements with a first gas sensing cell (FSC) of the set by activating the corresponding heater to heat the assigned sensitive element , while at the same time leaving the heater of another gas sensing cell (OSC) of the set inactive or activating this heater solely for conducting a reference gas measurement at a rate less than the conducting of gas measurements by the first gas sensing cell, - in response to a trigger (TR1), conducting gas measurements during a second period (T2) in the lifetime of the gas sensor following the first period (T1) with the other gas sensing cell (OSC) by activating the corresponding heater to heat the assigned sensitive element , while at the same time leaving the heater of the first gas sensing cell (FSC) inactive or activating this heater solely for conducting a recovery gas measurement at a rate less than the conducting gas measurements by the other gas sensing cell, wherein the conducting of a gas measurement includes measuring an electrical resistance (R11) of the subject gas sensing cell during activating or after having activated the corresponding heater , and wherein the trigger (TR1) is generated by the control unit dependent on one or more of a value of the electrical resistance (R1) measured and a change in the measured electrical resistance value (ΔR1) exceeding an assigned threshold in response to activating the heater . <EOS>