PURPOSE: To make a working efficient by providing a graphic display device capable of displaying a graphic or the like of full size at a real time by specify ing a position and plotting it on a transparent coordinate input board unitedly with the back of the transparent board.

CONSTITUTION: In the case of using an input device, an operator, a designer, etc., specify a position and plot a graphic or the like on the transparent coordi nate input board 1 by means of a stylus pen 8a. In this case, the position speci fied by the pen 8a is inputted to an A/D conversion controller 12 as the analog signal of X-Y coordinate value positional information by the action of coordinate lines 9 through an X-axis side output means 24 and a Y-axis side output means 25. The positional information is inputted to a computer 13 as a digital signal and stored. Processing such as expansion, contraction and edition can also be executed as necessary. Then, the positional information is inputted from the computer 13 to the graphic display device 2 as a digital signal through a graphic display device controller 14 and the graphic or the like of full scale whose position is specified by the pen 8a is displayed on the screen of the device 2 at the real time.