PURPOSE: To prevent sense even when a hand is put on the tablet and presses it in the case of description using a light emitting pen concerning the optical tablet.

CONSTITUTION: This is composed of a tablet 1 and a light emitting pen 2. For the tablet 1, a light guiding path 11 is composed of a transparent high polymer material containing fluorescent color, the side space and lower side wall of the plural light guiding paths 11 arranged in the shape of stripes are embedded by a reflecting member 12 composed of a high polymer material, and an array- shaped photodetector 19 is provided at one terminal part of each light guiding path 11 at least. The light emitting pen 2 is a describing means to generate signal beams 4 for generating fluorescent beams 3 from a tip 21 of the pen by stimulating the fluorescent color contained in the light guiding path 11. When the tip 21 of the pen is slid on the surface of the tablet 1 and executes description, the fluorescent beams 3 are made incident from the upper side wall of the light guiding path 11.