Bataclan nightclub mass killer Salah Abdeslam's decision "does not mean that he agrees with the verdict and the resulting life sentence without parole", his lawyers Olivia Ronen and Martin Vettes said Tuesday.
"He has simply resigned himself to it," they said on Twitter.
The life-sentence decision of the special court handling the cases for the self-proclaimed Islamic State fighter "has now acquired permanent status and there will not be an appeal trial", he said.
"Although such a punishment is unacceptable, we respect the decision of the one we have been assisting," they said, adding: "There is no honor in condemning somebody who is defeated by despair."
On June 30, Abdeslam was sentenced to life in prison with only a tiny chance of parole after 30 years, the toughest possible punishment under French law, which had only been pronounced four times previously since entering into law in 1994.
The 19 others sentenced for their role leading up to and following the attacks also declined to appeal, prosecutor Remy Heitz told AFP.
They had 10 days to lodge any appeal after their sentencing, a deadline that expired at midnight Monday.
The trial, with its 148 days in court, was the biggest in modern French history, the culmination of a six-year international investigation whose findings run to more than a million pages.
All of the attackers except for Abdeslam blew themselves up or were killed by police during or after the assault.
Abdeslam had begun his court appearances last September by defiantly declaring himself as an "Islamic State fighter" but finished tearfully apologizing to victims and asking for leniency.
n his final statement, he urged the judges not to give him a full-life term on the basis that he had not actually killed anyone, basing that claim that he discarded his suicide belt on the night of the attack and fled back to his hometown, Brussels.
"I made mistakes, it's true. But I'm not a murderer, I'm not a killer," he said.