To provide a numerical value setting device which can set and change the numerical value in a comparatively short time just with rotations of a rotary knob.

A controller 13 monitors the output pulses of a rotary knob 12 to detect the rotational direction and amt. of the knob 12. A speed detector 15 detects the rotational speed of the knob 12. The controller 13 controls the numerical value of the lowest order digit of a numerical display device 10 according to the rotational direction and amt. of the knob 12 when its rotational speed is lower than 1/2 cycle per pec. Then the controller 13 controls the numerical value of the 2nd digit of the display device 10 when the rotational speed of the knob 12 is higher than 1/2 cucle per pec. Furthermore, the controller 13 controls the numerical value of the 3rd digit when the rotational speed of the knob 12 exceeds 1 cycle per pec. Thus the rotational amt. of the knob 12 is increased to control the rotational speed by 1 as the digits have higher orders. If the numerical value of digits get out of a range (0 to 9) when these digit values are controlled, the numerical value of higher order digits are changed by a carry-up or carry-down operation.