The Wales team have come in for heavy criticism after a series of lacklustre performances in this season's Six Nations Championship.
But Thomas insists the team's set-piece performances have been up to scratch.
He said: "The lineouts went a lot better than many people might have thought (against Italy).
"We won 20 out of 24 which is an 83% success rate.
"The lineout isn't an issue and it has been improving every game. It's up there with the best teams in the world."
The Cardiff Blues hooker goes into Saturday's clash against Championship-chasing France expecting the Wales forwards to perform creditably at the set-piece.
"We will go into the France game looking at the positives," he said.
"The France-England game was pretty scrappy, but I think France are playing well at the moment and when they put things together they are a dangerous team.
"They have great skills, great runners and their forward pack is really strong.
"They are fighting for the championship and they deserve to be up there.
"Along with Italy, France have one of the strongest scrums in the championship. We did well against Italy so there is no reason why we can't hold our own against the French."