It's certainly a Gitane, made in Nantes, France. Gitane has produced many top-notch racing bikes, and has probably won more Tour De France's than any other manufacturer. Even their cheapest bikes were at least mid-range.
Are those the old "Suicide shifters" on the seatstays? Or is it a chain-grabber for wheel changes? whatever it is, it's certainly 40+ years old. Is the bike a fixed/free with a flip-flop hub? Those bars look like pre-war or maybe immediately post-war.
Where is JohnE whenn you need him?? Could you post some bigger pics-with close-ups of the rear hub, saddle, lugs, etc?