To automate a dehydrator/dryer by enabling the dehydrator/dryer to continuously dehydrate and dry slurry by providing a drum screen which centrifugally dehydrates the slurry, a heating section which evaporates moisture, by heating a slurry layer formed by a centrifugal force, etc., and sticking to the internal surface of the drum screen and dropping and discharging the slurry after drying and shrinking the slurry.

Slurry is introduced from an introducing section 8 and stuck to the internal surface of a drum screen 2 in the form of a cylindrical sticking layer 4 by utilizing a centrifugal force which is generated as the drum screen 2 is rotated by means of a driving section 3. When a dehydration detecting means 100 detects that the sticking layer 4 is nearly completely dehydrated, a control section 9 reduces the number of revolutions of the drum screen 2 and, at the same time, drives a heating section 5 and an air blowing means 6. Then the control section 9 separates the sticking layer 4 from the internal surface of the drum screen 2 as it is by drying and shrinking the layer 4 by supplying warm air to the layer 4 and make the layer 4 to drop down from an opening 11. Therefore, the slurry can, be dried continuously and automatically.