Fuel cell, intended to be supplied with reagent gases, comprising: ∘ several electrochemical cells, including at least one so-called characterization cell, coplanar to one another, comprising: • a same electrolytic membrane and • two same holding plates (40, 50) disposed on either side of the electrolytic membrane, each comprising an insulating plate (41, 51), produced in an electrically insulating material, in which are formed fluidic distribution channels (42, 52), and through which extend conductive vias (46, 56); ∘ a distribution electrical circuit, suitable for supplying an electrical load with an electrical current generated by the electrochemical cells; ∘ a monitoring device, comprising: • a first sensor for measuring a reference electrical signal representative of the performance levels of the fuel cell, • at least one connector, suitable for connecting the characterization cell to the distribution electrical circuit or to a characterization device, • a first processing unit, connected to the first measurement sensor and to the connector, suitable for detecting a reduction of the performance levels of the fuel cell from the measured value of the reference electrical signal, and, if necessary, commanding the connection of the characterization cell to the characterization device, ∘ a characterization device, comprising: • an electrical source of an excitation electrical signal, connected to the characterization cell, • a second sensor for measuring a response electrical signal, connected to the characterization cell, • a second processing unit, connected to the electrical source and to the second measurement sensor, and suitable for characterizing a pollutant present in at least one of the reagent gases from at least the measured response electrical signal. ∘ several electrochemical cells, including at least one so-called characterization cell, coplanar to one another, comprising: • a same electrolytic membrane and • two same holding plates (40, 50) disposed on either side of the electrolytic membrane, each comprising an insulating plate (41, 51), produced in an electrically insulating material, in which are formed fluidic distribution channels (42, 52), and through which extend conductive vias (46, 56); • a same electrolytic membrane and • two same holding plates (40, 50) disposed on either side of the electrolytic membrane, each comprising an insulating plate (41, 51), produced in an electrically insulating material, in which are formed fluidic distribution channels (42, 52), and through which extend conductive vias (46, 56); ∘ a distribution electrical circuit, suitable for supplying an electrical load with an electrical current generated by the electrochemical cells; ∘ a monitoring device, comprising: • a first sensor for measuring a reference electrical signal representative of the performance levels of the fuel cell, • at least one connector, suitable for connecting the characterization cell to the distribution electrical circuit or to a characterization device, • a first processing unit, connected to the first measurement sensor and to the connector, suitable for detecting a reduction of the performance levels of the fuel cell from the measured value of the reference electrical signal, and, if necessary, commanding the connection of the characterization cell to the characterization device, • a first sensor for measuring a reference electrical signal representative of the performance levels of the fuel cell, • at least one connector, suitable for connecting the characterization cell to the distribution electrical circuit or to a characterization device, • a first processing unit, connected to the first measurement sensor and to the connector, suitable for detecting a reduction of the performance levels of the fuel cell from the measured value of the reference electrical signal, and, if necessary, commanding the connection of the characterization cell to the characterization device, ∘ a characterization device, comprising: • an electrical source of an excitation electrical signal, connected to the characterization cell, • a second sensor for measuring a response electrical signal, connected to the characterization cell, • a second processing unit, connected to the electrical source and to the second measurement sensor, and suitable for characterizing a pollutant present in at least one of the reagent gases from at least the measured response electrical signal. • an electrical source of an excitation electrical signal, connected to the characterization cell, • a second sensor for measuring a response electrical signal, connected to the characterization cell, • a second processing unit, connected to the electrical source and to the second measurement sensor, and suitable for characterizing a pollutant present in at least one of the reagent gases from at least the measured response electrical signal.