The home in the southeastern town of La Terrasse, about 30 km from Grenoble, had about 80 residents.
Police said the fire at the Les Solambres residence broke out in one of the residents' rooms yesterday but that the reason was still unknown.
About 100 fire fighters and police officers evacuated most of the residence which was being searched for possible other victims.
About 50 of the survivors were taken to a communal hall while the others who lived in a separate wing of the home were allowed to stay in their rooms.