a lower part of the aircraft however the orientation of the principal duct is not sufficient to discharge all the impurities which may be deposited on the inner walls 1 of the principal duct 5 fig2 shows in transverse cross section an air inlet of a sensor of static pressure ps having a cleaning device according to the invention the pressure sensor is fitted for example to the same aircraft as that indicated in fig1 in this case the air inlet of a static pressure sensor comprises a mechanical interface module 100 u2032 whose outer surface is an extension of the skin surface of the aircraft 101 a principal duct 5 u2032 inserted into the module 100 u2032 the principal duct 10 u2032 comprises an axis running in a direction z the cleaning device according to the invention which is housed in the principal duct 10 u2032 a secondary duct 10 which comprises an external shape enabling it to be housed in the principal duct 5 u2032 and an internal shape similar to that of the inner walls of a principal duct 5 u2032 according to the prior art the secondary duct 10 is movable with respect to the principal duct 5 u2032 and the secondary duct 10 comprises an axis identical to that of the principal duct 5 u2032 the secondary duct 10 is extended by an auxiliary duct 6 to convey the air to the pressure sensor a main displacement device 20 which displaces the secondary duct 10 with respect to the principal duct 5 u2032 in the direction z a first embodiment of a secondary duct 10 is shown in fig3 in this first.