François Hollande has become president of France following a ceremony at the Elysée Palace in central Paris.
Hollande is the first socialist leader of France since François Mitterrand left office in 1995.
Hollande, 57, was elected to a five-year term in an election earlier this month, after voters ousted incumbent Nicolas Sarkozy after only one term.
Voters were disappointed over Sarkozy's handling of France's economy — which has high unemployment and low growth — and recoiled at his aggressive personality.
Hollande plans to leave shortly on his first diplomatic foray — to Berlin, where he is meeting German Chancellor Angela Merkel for a critical meeting on austerity and growth in Europe.
Arriving Tuesday morning at the 18th-century palace that is the traditional residence of French presidents, Hollande was greeted by Sarkozy on the Elysée's red-carpeted steps. Following a 40-minute private meeting with Sarkozy, Hollande was declared president after the head of the constitutional court read out the final results of the May 6 election.
In his first presidential speech, Hollande promised to fight financial speculation and "open a new path" in Europe, but acknowledged that he inherits huge government debt. He has pushed back against austerity measures championed by Germany amid Europe's debt crisis and wants government stimulus instead.
Hollande also pledged to bring "dignity" to the presidential role — something voters felt that Sarkozy did not always do.
Guests at the ceremony included France's leftist political elite, France's chief rabbi, the head of an umbrella group of French Muslim organizations, the daughter of late president François Mitterrand's mistress and a host of cultural figures.
Hollande received the insignia of the Grand Croix from the hands of Gen. Jean-Louis Georgelin, who heads the prestigious Legion of Honour, and the necklace of the Great Master of the Order of the Legion of Honour. Each linked medallion of the necklace bears the name of a president, with Hollande's name recently added.
Sarkozy left the palace hand-in-hand with wife Carla Bruni-Sarkozy, had a last handshake on the palace steps with Hollande, then was driven away. Former staffers who gathered in the palace courtyard applauded loudly as Sarkozy left.