To provide a drying furnace capable of improving the efficiency in a drying process to improve the production efficiency.

A furnace main body is constituted by vertical three stages, an intermediate stage position is applied as a conveying level of a longitudinal device, and a lifting conveyor Li of two stages having a common pitch structure to a conveying line pitch of the furnace main body, is installed as the lifting conveyor for loading and unloading substrates a-c between the conveyor of the longitudinal device and the furnace main body. Or the furnace main body is constituted by vertical two stages, an intermediate position of the upper and lower stages is applied as the conveying level of the longitudinal device, and the lifting conveyor of two stages having the common pitch structure to the conveying line pitch of the longitudinal device is installed as the lifting conveyor for loading and unloading the base between the conveyor of the longitudinal device and the furnace main body. In any case, the loading operation can be performed in parallel by another conveyor on a pass line in unloading to the stage except for the pass line, whereby one substrate can be sorted substantially in two steps, and a tact time can be shortened.