PURPOSE: To dry/roast grains, industrial materials, chemical materials, etc., having a fixed powder-or pellet-like shape without irregularity in the drying/ roasting treatment of such objects when they are continuously dried/roasted.

CONSTITUTION: Objects 11 to be subjected to the drying/roasting treatment are moved forward on a deck 2, which is mechanically vibrated by a vibrating motor 4, as jumping layers being vibrated, mixed and inverted. The stirring and mixing of these jumping layers are more promoted by the deck 2 having, for example, saw teeth-like waveform-shaped protrusions 2A, thus increasing the mixing and stirring between the upper and lower layers of the jumping layers to obtain the objects which have been subjected to the uniform drying/ roasting treatment.