PURPOSE: To obtain an apparatus for dehydrating and drying a viscoelastic material in the form spongy conglomerate and containing large quantities of water, in which apparatus specific rotating shaft having a helical feed teeth on the outer circumferential surface is mounted in a cylinder that has a heating section between an opening and a material loading section.

CONSTITUTION: The forward end of the cylinder 16 is opened to have the opening 25, the material loading section 33 is situated on a position remote from the opening 25, and the heating section 35 that is heated by heaters 32 is arranged between the opening 25 and the material loading section 35. The rotating shaft 44 extends in the cylinder 16, the base end of the rotating shaft 44 is connected with a rotation driving apparatus 6, and the forward end thereof extends to the opening 25 of the cylinder 16. The rotating shaft 44 has the helical feed teeth 46 on the outer circumferential surface, and the height of the teeth 46 extends close to the inner circumferential surface of the cylinder. A sequeesing section 36 is located between the loading section 33 and the opening of the cylinder 16 in such a way that the space between the inner circumferential surface of the cylinder 16 and the outer circumferential surface of the rotating shaft 44 is gradually narrowed toward the opening 25.