The court in Reims endorsed an earlier court decision to grant Lambert's wife, Rachel, and a coalition of local family support groups the right to decide whether he should continue to receive care.
In June a public prosecutor called for the right to decide to be given to two people who were not related to the 39-year-old former psychiatric nurse but the court rejected this option.
Rachel Lambert, along with five of his brothers and sisters and one of his nephews, wants Lambert, who has been unable to communicate since a motorbike accident in 2008, to be allowed to "die with dignity".
But his parents, Pierre and Viviane, who are devout Catholics, argue that he is not brain dead but handicapped.
They are supported by one of his sisters and his half-brother.
Parents to appeal
As soon as the latest judgement was announced, the parents' lawyer, Jean Paillot, said they would appeal against a decision he dubbed "astonishing".
The Reims hospital currently caring for Lambert has already said it would abide by the court's ruling.
His parents want him transferred to another establishment.
They are also fighting another court's order to the hospital to resume consultations with experts on whether to stop providing food and water.
Long legal battle
A previous consultation was interrupted in July 2015 when doctors announced they would appeal to legal authorities to decide who could best represent the patient's interest.
The Reims court described that move as "difficult to understand", since France's Council of State and the European Court of Human Rights had ruled that ending care was not a violation of Lambert's right to life.
Lambert's case has been the subject of a long legal battle in various courts and has focused attention on the debate over voluntary euthanasia.
For more background read European rights court ruling angers French anti-euthanasia campaigners