The SNCF Class Z 6400 electric multiple unit trains were built by Alsthom/Carel et Fouché from 1976 to 1979. They were chiefly used in commuter service to the Gare Saint-Lazare in Paris, serving the northwest Paris suburbs.
Seventy-five of these 4-car units were built for use on suburban service in the west of Paris, operating mainly on the Transilien Line L. The 4-car units were most often used in double-formation as 8-car sets. 43 sets had doors arranged for high platforms, while the remainder were for low platforms.
They were progressively replaced by the Class Z 50000 units with the last commercial service of the Z 6400 running on 4 November 2020. This was earlier than originally scheduled due to a downturn in passengers numbers during the COVID19 pandemic.