To reduce the baking and drying time of a work coated with a thermosetting coating material.

When works ( a work coated with a solvent based coating material and a work coated with a water based coating material) having a different required baking temperature from each other are baked and dried in the same drying oven 12, air heated to a temperature corresponding to the work having a higher baking temperature by a heater 22 is blown to the work 10 by a blower 26. At this time, the flow rate of the air blown (hot air) to the work 10 is controlled corresponding to the required baking temperature of the work 10. Because a mutual relation is present between the surface temperature (baking temperature) of the work 10 and the flow rate of the air, the surface temperature of the work 10 is set to the required baking temperature by controlling the flow rate of the air. As a result, the baking time is reduced compared with that in the case the temperature of air is directly controlled.