Belgian jihadist Abdelhamid Abaaoud, 27, is believed to have been the ringleader of last Friday’s massacres which left 129 dead.
Forensic experts were trying to determine whether a body recovered following a major pre-dawn raid on a flat in the northern suburb of Saint-Denis was that of Abaaoud.
In a statement, the Paris prosecutor’s office confirmed that Abaaoud died in the raid and his body had been identified based on skin samples.
Police confirmed that a female suicide bomber who blew herself up during the gunfight was Abaaoud’s cousin, Hasna Aitboulahcen
One official said Aitboulahcen is believed to have detonated a suicide vest after a brief exchange with police officers.
According to the official, one of the officers asked: “Where is your boyfriend?” and she responded angrily: “He’s not my boyfriend!” before there was an explosion.
The bodies recovered in the raid were badly mangled, with part of the woman’s spine landing on a police car, complicating formal identification.
She is believed to be the first female suicide bomber to hit western Europe.
Eight people were arrested after a second attack was foiled when Swat teams laid siege to the flat for seven hours on Wednesday.
Paris prosecutor Francois Molins said the operation neutralised a “new terrorist threat”, and that “everything led us to believe that, considering their armaments, the structured organisation and their determination, they were ready to act”.
The jihadis were set to carry out a second attack targeting Charles de Gaulle airport and the city’s financial district La Defense, according to reports.
Salah Abdeslam, one of the suspected gunmen who is now the focus of an international manhunt, was not among those arrested, the prosecutor added.
The French military said it had destroyed 35 Islamic State targets in Syria since the militant group claimed responsibility for last Friday’s attacks.
Belgian authorities today launched six raids in the Brussels region linked to Bilal Hadfi, one of the suicide bombers outside the Stade de France.
Meanwhile, French prime minister Manuel Valls warned that terrorists could use chemical or biological weapons, and urged an extension of France’s state of emergency.
He said: “Terrorism hit France, not because of what it is doing in Iraq and Syria ... but for what it is.
“We know that there could also be a risk of chemical or biological weapons.”
Belgian police are reportedly searching for a man named Mohamed K, from Roubaix, northern France, who is suspected of supplying the terrorist gang with explosives.
Wednesday’s raid was launched after a discarded mobile phone and tapped telephone conversations allowed investigators to identify a series of safe houses, with the suggestion that Abaaoud may have been holed up in an apartment less than a mile from the Stade de France, where one of the terror attacks took place.
Police fired about 5,000 rounds of ammunition during an early-morning exchange of gunfire which lasted about an hour as the terrorist cell barricaded themselves in the hideout.
Heavily armed police squads were initially thwarted by an armoured door and had to use assault guns, sniper rifles, grenades and explosives during the “extremely difficult” and “complex” operation.
The eight arrested included one woman and a man whose flat was used as a hideout by the terror cell and are being interrogated.