Sandrine Mouleres, 31, was fined 22 euros in April by police who said she did not have a clear field of vision.
Jean-Michel Pollono, Mouleres' attorney, said the court in Nantes had ruled "we are in a free country, and as a result, everything that isn't forbidden is allowed."
The case made headlines when Moulères’s husband, Lies Hebbadj, who has four female companions including his lawful wife, was accused of polygamy by Interior Minister Bryce Hortefeux.
Hortefeux threatened to strip the Algerian-born man of his French passport, and he was later charged with welfare fraud and violating labour laws.
Five to six million Muslims live in France, but the burqa or niqab concerns only a tiny minority of women, less than 2,000 according to official estimates.