That's a French Inter, presented at the Salon de Paris in 1953. It was produced by aircraft factory SNCAN (Societé Nationale de Constructions Aéronautiques du Nord). It had a rear mounted 175 cc one-cylinder two-stroke Ydral engine and was able to reach 80 km/h.
A few hundred of these were built until 1956, some were even sold 'new' as late as 1958, and also some were sold outside of France (i.e. in Switzerland)