The court in Nanterre, where the FN's headquarters is situated, said the far-right party did have the right to expel Jean-Marie Le Pen, its leader and presidential candidate for nearly 40 years.
But it went on to rule that he remains its honorary president, a post created for him when Marine Le Pen took over the party's reins in 2011.
That means that he must be invited to and can participate in party committee meetings.
The FN will be fined 2,000 euros for each time it does to comply with the ruling.
Battle with daughter
Since 2011 the pair have fallen out over Marine's plans to revamp the party's image and Jean-Marie was suspended from membership in 2015 after boycotting a disciplinary hearing for repeating his assertion that the Nazi Holocaust gas chambers were a "detail of history" and refusing to describe wartime collaborationist leader Marshal Philippe Pétain as a traitor.
He won a first legal case against his suspension and another that suspended a vote of members on constitutional changes that would have abolished the honorary presidency.
The FN counted the votes anyway, finding that 94 percent of participating members have approved the proposal.
The court fined it 15,000 euros for having prevented Jean-Marie Le Pen from exercising his functions as honorary president and for publishing the results of the vote.
Presidential election 2017
In August 2015 the party's executive committee expelled Jean-Marie Le Pen at a meeting that Marine Le Pen and her close ally Florian Philippot did not attend.
Since then he has set up an organisation that plans to stand candidates in the 2017 legislative elections, although he appears to back his daughter's candidacy in the presidential elections, while judging that Donald Trump's election in the US proves that her strategy of cleaning up the party's image is an "idiocy and an impasse".
Marine on Thursday said that Trump has her phone number "if he wants to meet me tomorrow" and that they have a number of friends in common.