In a speech to her National Rally party, at a meeting that it billed as the launch of her presidential campaign, Le Pen said she would abolish a 2017 law that banned the issuing of new exploration permits for hydrocarbons, in favour of renewable energies.
It also banned exploration and extraction of shale gas. The law was named after Nicolas Hulot, a former environment minister.
Le Pen called it "the stupid Hulot law."
Le Pen's nearly hour-long address to supporters gathered in the city of Orleans went back over her familiar nationalist, anti-immigration themes, centred around her view that France has been ruined by its leaders but that she can give it a brighter future.
"The fires are going out of the old great parties, my friends, and they're stirring on a pile of ashes," she said.
"We're living not the end of the world but the end of a world, of their world. It's up to us to reinvent the one that is coming," she added.
The 58-year-old Le Pen is making her fourth campaign for the French presidency.
She is seen as the current favourite to succeed President Emmanuel Macron, who is constitutionally barred from seeking a third consecutive term.
Her supportive crowd shouted "We're going to win" and "Marine, president" as she spoke.
