Chirac, ending 12 years in power, transferred the country's nuclear codes to President Sarkozy in a behind-closed-doors meeting that was a highpoint of the transfer of power.
A 21-gun salute signaled the change in leadership after the 74-year-old Chirac took his leave with a handshake at the entrance of the ornate Elysee Palace and a walk alone to a waiting car. Sarkozy, with a clenched jaw, returned the waves before turning to enter his new home for the next five years.
The blunt-talking, pro-market Sarkozy, 52 the sixth president of the Fifth Republic that was founded by Charles de Gaulle in 1958 was elected on May 6 on pledges of market reforms and a break with the past.
In his first speech as president, a determined Sarkozy noted that he was elected with a mandate for change that he was honor-bound to fulfill.
"The people conferred a mandate on me .... I will scrupulously fulfill it," he said, adding that further delays "will be fatal."
Chirac handed over the helm of the world's sixth-largest economy after two mandates marked by lackluster reforms and tensions in rundown, immigrant-packed housing projects far from the glory of the Elysee Palace.
Issues demanding attention include a jobless rate of more than 8 percent and the identity and cohesion of an old nation in a quickly changing world.
"Never has opposition to change been so dangerous for France," Sarkozy said, promising to restore the values of "work, effort, merit" and to invent new solutions.
Sarkozy said that issues of security, order, authority and results would be priorities of his administration.
Even before taking office, Sarkozy sought to set himself apart from Chirac, holding surprising preinaugural meetings with labor unions and some leading Socialists.
Sarkozy is expected to appoint a fellow conservative, four-time former minister Francois Fillon, as prime minister in the coming days.
The popular Bernard Kouchner, a former Socialist health minister and founder of the Nobel-prize winning organization Doctors Without Borders, is among those being considered for the post of foreign minister.