Rodolphe Bosselut said Le Pen had been summoned by investigating magistrates in Paris and that they had, “as expected, charged her”, adding that she would appeal.
A judicial source told AFP she had been charged with breach of trust over the salaries paid to her chief of staff Catherine Griset and her bodyguard Thierry Legier and for complicity in breach of trust as FN leader.
If tried and convicted, Le Pen faces up to three years imprisonment and a fine of up to 375,000 euros ($425,000), although it is unlikely she would receive a custodial sentence.
The 48-year-old National Front leader, who made a failed run for president this year, invoked her immunity as a member of the European Parliament in refusing to answer questions from investigators during the campaign.
She had however promised to cooperate with the investigation after the May presidential and June parliamentary elections were over.
At Friday's meeting with the magistrates, she read out a declaration and declined to answer questions, as allowed by the law, her lawyer told AFP.
Investigators suspect the FN used money from Brussels earmarked for parliamentary assistants to pay staff for party work in France.
The European Parliament claims it was defrauded of up to five million euros.
Griset and another FN assistant have already been charged with covering up breach of trust.
Le Pen was first elected to the European Parliament in 2004.
She is one of 17 National Front lawmakers — along with her father Jean-Marie Le Pen, from whom she is estranged, and her partner, FN vice-president Louis Aliot — being investigated over salaries paid to around 40 parliamentary assistants.
Macron allies probed
The centrist MoDem party, which is allied to President Emmanuel Macron's Republic on the Move party, has been targeted in a preliminary probe over similar allegations involving assistants' salaries.
Le Pen, an anti-EU nationalist, beat the candidates of the traditional right and left to secure a spot in May's presidential run-off against Macron, a pro-EU centrist.
But she was soundly beaten by Macron in the second round, by 66.1 to 33.9 percent.
Her legal woes took a back seat during the campaign to the scandal ensnaring her conservative rival Francois Fillon, whose wife was paid nearly 700,000 euros for a suspected fake job as a French parliamentary assistant.
In legislative elections held directly afterwards she was elected to the National Assembly for the first time, winning a seat in the northern former coalmining region of Pas-de-Calais.
In April, The Local reported that the European Parliament believed the fake jobs scandal involving Marine Le Pen's National Front (FN) party cost the institution nearly €5 million ($5.5 million), according to a source in the French press at the time.
The cost of the scandal, which involves the employment of assistants and a bodyguard, rose to €4,978,122 after “new information” was discovered, a source told AFP.
The previous cost was estimated at €1.9 million.
Earlier during April, French prosecutors asked the European parliament to lift the immunity of far-right presidential candidate over the inquiry into alleged fake parliamentary jobs.
The demand was made after she invoked her parliamentary immunity in refusing to attend questioning by investigating magistrates on March 10.
The case is linked to an expenses inquiry in which the European Parliament has accused Le Pen's FN of defrauding it to the tune of some €340,000 ($360,000).
The parliament believes the party used funds allotted for parliamentary assistants to pay Le Pen's personal assistant Catherine Griset and her bodyguard Thierry Legier for party work in France.
French investigators leading the case raided the party's headquarters outside Paris in March in a bid to determine whether the FN used European funds to pay for 20 assistants — presented as parliamentary aides — who were working for the party elsewhere.
Le Pen shrugged off the request to have her immunity lifted, saying it was “normal”.
“It's totally normal procedure, I'm not surprised,” she told Franceinfo radio.
The allegations appear to have had little impact on Le Pen's campaign.
Investigators probing the allegations against the FN also raided the party's headquarters outside Paris.