The invention concerns a device for measuring the concentration of endogenous NO in the nasal cavities, comprising an analysis circuit (25) for analysing the airflow passing from one nostril to the other and a circuit (26) compensating for the air drawn in by the analysis circuit, said circuits each being provided with a pump (21, 29) and comprising a flow sensor (23).Linvention concerne un dispositif pour la mesure de concentration en NO endogène dans les cavités nasales comportant un circuit danalyse (25) du flux dair passant dune narine à lautre et un circuit de compensation (26) de lair aspiré par le circuit danalyse, lesdits circuits étant munis chacun dune pompe (21, 29) et comportant une capteur de débit (23).
