To provide a coating drying furnace excellent in the baking drying properties of an underbody region.

In a coating drying furnace 1, a coating material applied to a car body 3 is baked and dried. In this case, a hot air blowoff port 20 provided so as to upwardly blow off hot air along the inner side wall surface of the furnace and hot air guides 15, 17 provided to the side wall and/or ceiling of the furnace and deflecting hot air toward the interior of the furnace from the hot air blowoff port 20 through the side window opening parts 33 of the car body are provided.