In a vibratory sieving machine having two rotary shafts provided with eccentric spindles disposed parallel to each other, motors are disposed so as to reduce the capacity or power consumption of the motors required in the vibratory sieving machine, and to drive the two rotary shafts independently, and a rotary drive control mechanism is configured such that either one of the two rotary shafts can be started upon a start, while the other of the two rotary shafts can be started after a rotary drive state of the one of the two rotary shafts is transferred to a stationary state.