The French Football Federation (FFF) is set to decide over Domenech's future after France's qualifier against Romania on October 11th.
"If we don't get to the World Cup, I agree, you change. But not before that," Gallas told L'Equipe on Wednesday.
"If we change will it be better? Who can be sure of it? Nobody. I'm for continuity. You start with someone and you stay with them until the end.
Domenech escaped the sacking when the French Federation decided to give him a confidence vote following the team's early elimination at EURO 2008.
"During the Euro it didn't go very well, but now we are on a new adventure."
"We are behind the coach. We have started with him and we will end with him," added the Arsenal skipper.
France's start to the qualifiers didn’t offer Domenech any favors as the team are fourth in group seven after an away loss to Austria and a home win over Serbia.