To improve accuracy in the stopping position of a load and at the same time run a load smoothly by preventing excessive, increased speed of the load.

A roller device 11 is provided with a rotary speed detection element 21 for detecting the rotary speed of a motor 15 and outputting a rotational speed signal Sv corresponding to the rotary speed, and a control part 22 for calculating the rotational speed of the motor 15 based on the rotational speed signal Sv, comparing the calculated rotary speed of the motor 15 with a preset reference rotational speed, and suppressing the increase in the rotational speed of the motor 15 when the rotational speed exceeds the reference rotational speed. When a brake is to be operated when switching between normal rotary control and brake rotary control, gentle braking is initially applied, while when the brake is to be released, braking operation in the normal rotational control is reinforced, thus preventing the rotational speed of the motor 15 from fluctuating greatly and running of a screen is conducted smoothly.