PURPOSE: To enable the input of position coordinates with good accuracy and precision even to graphic information having a fine construction, by providing a magnifying lens which magnifies the pen tip to make it visible to the main body of a tablet pen.

CONSTITUTION: A position coordinate detecting mechanism is assembled to a pen tip 2a of a tablet pen main body 2, and a designated position of the pen tip 2a to a tablet plane 1a is detected and inputted to a computer system or the like. The tablet pen main body 2 like this is provided with a magnifying lens 4 supported by a holder 3. Thus, when the pen main body 2 designates the position of the tablet plane 1, the image in the vicinity of the pen tip 2a can be observed with magnification.