Great news for future travelers heading to Mongolia! Kazakhstan's airline
Air Astana will launch an Astana–Ulaanbaatar route starting June 1, 2016, making it possible to reach Mongolia in record time.
This announcement comes six months after the opening of the direct Paris CDG–Astana connection, Kazakhstan's capital, with departures on Wednesdays, Fridays, and Sundays, backed by premium onboard service.
Taking into account time differences and connections between Astana and Ulaanbaatar, two departures are possible from Paris: Wednesdays and Sundays at 7:20 PM, while the return is necessarily from Ulaanbaatar on Sundays at 11:25 AM... Very convenient times indeed, with
less than 2 hours of layover each time!
Quick summary table:

Those who wish can also stop in
Almaty to discover Kazakhstan, from
€67 all-inclusive (StopOver Holidays supplement until December 31, 2015).

If you have questions about
Air Astana, which is quite understandable given that it's not widely known in English-speaking markets, know that it has been operating since 2002 and has been regularly voted "Best Airline in Central Asia and India" since 2012 (Skytrax).
This will be the 2nd direct connection between Mongolia and Central Asia, following
Turkish Airlines, which has operated the Bishkek–Ulaanbaatar route for several years now.
All of this represents an excellent opportunity for English-speaking travelers to visit the land of Genghis Khan at a lower cost, as the airline announces fares well under
€700 all-inclusive.
More information on the official website:
http://www.airastana.com/fra/fr-FR