To lessen power consumption to miniaturize a device by feeding power into an electric motor when power supply to the electric motor is stopped on rotating a dehydrating basket and transmitting the power generated on slowdown to a power supply means or a storage means by a storage control means.

When power is fed from a power supply means 3, an electric motor 4 is rotated, and with it, a dehydrating basket in a dehydrating vessel 5 is rotated. During the rotation of the dehydrating basket, centrifugal force is generated in the dehydrating vessel 5 to separate a solid-liquid mixture into a solid and liquid. And even after power supply from the power feeding means 3 is stopped, the dehydrating basket is rotated by inertia, but a rotating shaft of the electric motor 4 is also rotated to perform power generation in the electric motor 4. A storage control means 6 transmits this power to the power supply means 3 or a storage means 7. The electric motor 4 generally consumes the power most when started, but at this time, the power is fed from both the power supply means 3 and storage means 7.