A dehydrator for use in washing clothes or the like includes a dehydration tub mounted in an outer cabinet, a brushless motor for rotating the dehydration tub for a dehydrating operation, and a microcomputer-based controller for controlling the rotational speed of the motor so that the motor is rotated at a plurality of different rotational speeds sequentially during the dehydrating operation. The different rotational speeds include a maximum rotational speed ranging between a rated rotational speed or above and a rotational speed corresponding to a resonant point of the outer cabinet.