<p>A notebook device is provided which allows a user to write a note on a paper sheet, which is capable of properly converting and storing the note in electronic form, and which allows the user's writing operation on the paper sheet in a natural manner even when such storage in electronic form is achieved. The notebook device includes: a notebook having paper sheets bound together; a rectangular frame-shaped optical waveguide surrounding at least part of the paper sheets; and a storage means for storing therein the path of movement of a tip of the writing implement as electronic data when a writing operation is performed on part of the paper sheets revealed within the frame of the optical waveguide with the writing implement. The optical waveguide includes first and second sections opposed to each other in the form of the frame.</p>
