A float bath for manufacturing a float glass includes a brick assembly composed of a plurality of bricks storing a molten metal so that a float glass is capable of moving forward while floating on the molten metal, a bottom casing for forming an outer side of the brick assembly, and an air blower installed away from the bottom casing to supply a cooling air toward the bottom casing. The air blower includes a plurality of nozzles having a diameter of about 30 mm and arranged with a pitch of about 250 mm to about 300 mm in order to cool the bottom casing to a predetermined temperature.