PURPOSE: To effectively dry granulated matter, by converting the energy to supply air into the pressure inducing and decompressing effect by the rotating motion of a rotor, and into the frictional heat generating effect of the rotor in contact with the gas in the equilibrium state in the decompressing action.

CONSTITUTION: A hollow chamber 2, provided with a frictional heat generating mechanism 3 in the decompressed and equilibrium state, is constituted ventilatably by the intermediary of a granulated matter storing chamber 9 and a ventilating bottom plate 10. The mechanism 3 is communicated to the outer side of the chamber 2 by the intermediary of a hollow tubular chamber 7 which is provided in the chamber 9, and heating plates 8 are projected from the periphery of a hollow tubular chamber 7. A decompressed equilibrium state heating equipment 1 for granulated matter in such a structure as mentioned above is provided in a hollow body 14. The mechanism 3 effectively drys the granulated matter 13 by heating it, at the same time, by reducing the pressure in the chamber 9. In addition, a decompressing equilibrium state frictional heat generator 3' reduces the pressure inside the hollow chamber 14, and also heats the air in the same body 14, as a result, the dispersing effect of liberated water content from the granulated matter can be further increased.