The Amiot 140 was a twin-engined stressed skin bomber that was the precursor of the Amiot 143, one of the French bombers in service at the time of the German invasion in 1940. The Amiot 140 was designed in response to a French Air Ministry specification of 1928 that called for a twin-engined four-seat all-metal multipurpose monoplane. Four companies were awarded contracts to produce a prototype, amongst them the Société d'Emboutissage et de Construction Mécanique (SECM or Stamping and Mechanical Construction Corporation), led by Félix Amiot. Although the aircraft eventually took Amiot's name, it was designed by a team led by André Dutartre.
The Amiot 140M was undoubtedly an ugly aircraft, with a rectangular fuselage, large thick wing, awkward looking nose and a large glazed gondola below the superstructure, but it did have the performance required by the French Armée de l'Air. After making its maiden flight on 12 April 1931 the Amiot 140 underwent tests at CEMA (the Air Material Research Centre at Villacoublay) and took part in night manoeuvres in July 1933, before on 23 November the Armée de l'Air placed an order for 40 aircraft. Two re-engined prototypes - the Amiot 142 and Amiot 143 were built, and it was the second design, powered by air-cooled radial engines, that entered service as the Amiot 143M.