The nine member jury, headed by Nanni Moretti, selected the film from 21 other strong entries for the big prize. Haneke won the Palme d'Or for 'The White Ribbon' in 2009.
"I thank my wife, who has been putting up with me for years. This film is in part an illustration of the promise that we made to each other. A big thank you to my two actors. They are the essence of this film," the 70-year-old director said as he took the stage with film's lead actors Jean-Louis Trintignant and Emmanuelle Riva amid a standing ovation.
81-year-old Trintignant, plays a Parisian husband caring for his dying wife, played by 85-year-old Riva. Both are iconic figures in French cinema.
Festival's second prize, the Grand Prix was awarded to Matteo Garrone for his film 'Reality'.
Another festival favourite, Ken Loach, won the Jury Prize for his 'The Angels' Share'.
"I'd like to thank the Festival and the Jury, who have been very kind!... I wish to say that Cannes shows us that the cinema is not just entertainment