Ali Ben Bongo also said he wanted an end to corruption and injustice
Ali Ben Bongo has been sworn in as Gabon's new president two months after his disputed election.
"I want a Gabon where the elites circulate and are renewed," said the son of Gabon's long-time leader Omar Bongo in his inauguration speech.
The opposition cried foul after Mr Bongo was declared the winner, sparking protests in which several people died.
But on Monday, the Constitutional Court dismissed the opposition challenges to the official results.
In his speech, Mr Bongo also said he wanted an end to corruption and injustice.
The ceremony was attended by several presidents from Central and West Africa.
Nine opposition candidates had called for the vote to be annulled, arguing that there was widespread fraud.
The court ruled that Mr Bongo had won the election with 41.79% of the vote.
Veteran opposition leader Pierre Mamboundou came second with 25.64%, followed by former Interior Minister Andre Mba Obame on 25.33%.
Gabon is sub-Saharan Africa's fourth biggest oil producer and Africa's second biggest wood exporter, although most of its 1.4 million people live in poverty.
August's election was called after the death of Omar Bongo, one of the world's richest men, who had ruled the nation for four decades.