To loud applause the presidential hopeful said: "The European Union will die because the people do not want it anymore.
"We will change for another Europe, the European idea harmed by the federalists will re-energise itself, re-invigorate itself in the Europe of the people and ofthe nations."
She earlier sought to reassure voters concerned over her plans to withdraw the country from the euro zone, saying it "wouldn't be chaos" and she would seek "well-prepared" talks with other EU countries.
Marine Le Pen soaks up the applause at an election rally in Paris
The European Union will die because the people do not want it anymore
Marine Le Pen
Opinion polls show the anti-EU, anti-immigrant Front National leader qualifying for the April 23 first round of the presidential election but losing the May 7 run-off to centrist Emmanuel Macron.
Leaving the euro is one of Ms Le Pen’s flagship policies, both a mark of its anti-establishment stance that attracts voters angry with globalisation, and a likely obstacle to its quest for power in a country where a majority oppose a return to the franc.
She told Le Parisien newspaper: "The euro triggered a very serious increase in prices and a very steep drop in purchasing power.
"It is also a serious hindrance to job creation because it triggered a loss in competitiveness for the French economy."
Marine Le Pen predicts the end of the EU
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Marine Le Pen is expected to reach the second round of the French elections
However, 72 per cent of French voters oppose a return to the franc, according to an Ifop poll published in Le Figaro newspaper.
With previous opinion polls also showing such opposition, Ms Le Pen has said for months that she would not abruptly withdraw from the euro but instead hold a referendum after six months of negotiation with the rest of the EU on a range of issues including leaving the border-free Schengen agreement and reducing the EU to a loose cooperative of nations.
She specified in the Le Parisien interview that talks on the euro would come at the end of those negotiations, after Germany's general election in September.
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She said: ”It must be done in a rational, well-prepared way.
“I don't want chaos. Within the negotiation calendar I want to carry out the euro would be the last step because I want to wait for the outcome of elections in Germany in the autumn before renegotiating it."
The Ifop poll showed that, unlike voters overall, a majority of Front National voters back a euro exit.