Air France's carry-on luggage size requirements are all the same regardless of your travel class. You're allowed to bring onboard a carry-on bag that does not exceed 21.6 x 13.7 x 9.8 inches (55 x 35 x 25 cm) and a personal item that does not exceed 15.7 x 11.8 x 5.8 inches (40 x 30 x 15 cm).