The 26-year-old arrived early today for interrogation in central Paris under heavy security, escorted by military police, elite police units and a helicopter.
Authorities hope Abdeslam will be able to shed light on the operational details of the Paris attacks, as well as provide clues as to whether other cell members are still at large.
For months, Abdeslam was the most wanted fugitive in Europe until he was tracked down and arrested on March 18 in the Brussels neighbourhood of Molenbeek where he grew up. Transferred to France under high security on April 27, he has since been held at Fleury-Merogis prison, southeast of Paris.
A childhood friend of suspected ringleader Abdelhamid Abaaoud, Abdeslam is thought to have played a key role both on the night of the Paris attacks on November 13, and in their preparation.
Two others have been arrested in France in connection with the attacks carried out by the Islamic State group, but they are considered secondary participants. Abdeslam played a key role, dropping off the three suicide bombers who blew themselves up outside the Stade de France national stadium in northern Paris. He is thought to have backed out of blowing himself up.
Authorities found an abandoned explosives vest in a southern Paris district close to where mobile phone data placed him on the night of the attacks. CCTV pictures from petrol stations showed him fleeing back to Belgium after two friends came to pick him up.
He also played a critical role in the build-up to the attacks, renting the cars and hideouts used by the gang. He also transported several other jihadists around Europe in the preceding months, including Najim Laachraoui, the suspected bombmaker for the November attacks who was killed in a suicide bombing in Brussels on March 22.
The coordinated attacks in Brussels that day also struck a metro station, killing 32 people overall. French police hope Abdeslam could also shine light on the links between the attacks in Paris and Belgium, both carried out by a network linked to the Islamic State group.
His French lawyer Frank Berton told AFP that Abdeslam "wants to explain himself". But few are expecting any major revelations.
"The investigators have only him in custody. He could help if he collaborates, either to confirm elements of the investigation, or to give fresh leads," said Gerard Chemla, a lawyer representing some 50 of the victims and their families from the Paris attacks.