A turbojet for an aircraft includes an engine housed in a nacelle and a thermal exchanger that can be traversed by a hot fluid designed to be cooled by thermal exchange with a cold fluid external to the thermal exchanger. The thermal exchanger is disposed in an internal volume of the nacelle, between an internal wall of the nacelle and an external wall of the engine, in such a way as to present two thermal exchange surfaces in the flow of the air stream from the turbojet. The disclosed embodiments also relate to an aircraft equipped with such a jet turbine engine.