In 2015, eight people were killed in the fire in their building, rue Myrha in the 18th arrondissement of Paris, district of Goutte d'Or.
The trial of the alleged arsonist opens on Monday and is expected to last until December 11.
The accused had indicated that he was under the influence of "imaginary friends" at the time of his gesture.
The trial of the man accused of having caused the death of eight people in 2015 by setting fire to a building on rue Myrha, in the Parisian district of Goutte d'Or, opened on Monday in front of the court of 'Assises de Paris.
The court chaired by Emmanuelle Bessone began the hearing by drawing lots for the members of the jury made up of two men and four women.
The fire at the Myrha Street building on September 2, 2015, remains one of the deadliest arson attacks in the capital in recent years.
Eight people including two children aged 8 and 14 died in this disaster.
A gesture under the influence of "imaginary friends"
In the accused's box, Thibaud Garagnon, a young man with long brown hair held back by an elastic and wearing a gray printed t-shirt, confessed, during his custody, to having set fire to a stroller left in the entrance to the building.
Research on his computer revealed a lot of research on fires.
During his interrogations, he had not explained the reasons for his gesture, contenting himself to indicate that he was under the influence of "imaginary friends".
The trial is scheduled to last until December 11.