To provide a waste heat recovering method capable of efficiently recovering waste heat.

A conveying-out passage as a closed cross-section conduit 16 for conveying out an outbound vehicle 12B from a drying furnace 11, is divided into a first area 31, a second area 32, a third area 33 and a forth area 34 in the conveying direction, heat exchange takes place between the outbound vehicle 12B and atmospheric area of each of the areas 31-34 in these areas 31-34, the atmospheric area exchanging heat in the prescribed area 31-34 is conveyed to the area 31-34 closer to the drying furnace 11 with respect to the prescribed area 31-34, and the waste heat is recovered in the first area 31 adjacent to the drying furnace 11.