Drying furnace and coating drying method

A method for drying a coating film applied to a vehicle body by blowing the hot air while the vehicle body is being conveyed in the longitudinal direction in the furnace shell of the drying furnace where a plurality of the drying areas is provided along the longitudinal direction, characterized in that, each of the drying areas comprises:

• a means by which the hot air is discharged diagonally upward from the first hot air supply port arranged at a position below the vehicle body in the furnace shell, so as to dry the coating film of mainly the external parts including the outer floor side of the vehicle body;
• another means by which the hot air is discharged diagonally downward from the second hot air supply port arranged at a position higher than the first hot air supply port in the furnace shell, wherein such hot air is introduced into a room through a window of the vehicle body, so as to dry the coating film of mainly the internal parts including inner floor portion of the vehicle body;
• and
• yet another means by which the hot air is discharged to the outside of the furnace shell through an exhaust port arranged at a position lower than the first hot air supply port and the second hot air supply port in the furnace shell.