PURPOSE: To provide a system where document's content is not required to understand when a data base is constructed and where a user is not required input through a keyboard, etc., by magnetically or optically storing various information used for retrieving a keyword, etc., generated according to book the content of the or report, etc.

CONSTITUTION: As a reading means 3 which magnetically or optically reads the information in a storing part 2 provided to a book 1, photodetectors, for example, arranged in a two-demensional array which read series of dots are used, if the storing part 2 optically stores data. Thus, much higher resolution than that of print dots is obtained. The data which indicates series of dots thus read out is stored in a disk device 5 through a calculator 4. Sufficient data is stored in the book 1, especially in a patent announcement public report, and by reading the storing part 2 as required, a data base is automatically and easily constructed in a disk device 5.