PURPOSE: To provide an illuminating area control device for spotlight capable of controlling the illuminating direction of a spotlight and the opening angle of the illuminating light by designating the illuminating area.

CONSTITUTION: An illuminating area control device for spotlight is provided with each control motor 54, 55 for horizontal rotation and vertical rotation to control the illuminating angle of a spotlight 11. The device is further provided with a data input part 14; a resistor 16 of spotlight mounting position data for storing and setting the spotlight mounting position; a resistor 15 of illuminating area position data for storing and setting the illuminating area position; an arithmetic part 17; a FOCUS data resistor 18 for storing and setting the opening angle of the illuminating light; and a control motor 13 for controlling the opening angle of the illuminating light. From the mounting position data of the spotlight 10 inputted to the data input part 14 and the position data of two intersections between a vertical line including one point on the optical axis of the illuminating light and the edges of the illuminating area of the illuminating light, the illuminating direction and opening angle of the illuminating light are calculated by the arithmetic part 17, whereby the illuminating direction and opening angle of the illuminating light are controlled.