Features & Roles
Collection of Materials
A primary duty of the National Diet Library is to collect and preserve Japanese publications as they are the nation's cultural and intellectual assets. The NDL depends greatly on the legal deposit systemfor its collection of materials. Moreover, the NDL collects through purchase and donation books published before the legal deposit system came into existence, old materials, and foreign publications on Japan.
Book deposit
Japan's only deposit on library, the National Diet Library collects publications (including maps, phonographic discs and microfilms) published in Japan, with the help of the legal deposit system empowered by the National Diet Library Law. CD-ROMs and other "packaged" electronic publications became subject to the legal deposit system in autumn of 2000.
Under the legal deposit system, when publishing a book, the national or local government is required to deliver a prescribed number of copies to the NDL. Private publishers are required to deliver one copy of their new publications and, in return, are entitled to receive from the NDL an amount of money corresponding to the normal cost of publication (in principle, half the list price). All of the collected publications are registered into the National Bibliographyand its magnetic tape version JAPAN/MARC for circulation throughout Japan and abroad. At present the number of the collection has exceeded 37 million of which books are about 9.7 million.
*No distinction between Japanese and foreign-language books in statistics 1949.
Purchasing
In the case of Japanese books and periodicals which many people want to read, the National Diet Library purchases additional copies. It also purchases old materials and foreign publications in addition to those exchanged or donated. Accounting for a large percentage of the purchased foreign publications are periodicals in the science and technology field and books on social science.
Exchange and donation
A large portion of the foreign materials, especially the publications of foreign governments and international organizations, collected by the National Diet Library have been acquired through international exchange. Additionally there are many publications that were donated or bequeathed by individuals and groups.
Preservation of Materials
It is the responsibility of the National Diet Library to accumulate, as the cultural assets of the Japanese people, materials published within Japan and to hand them over to future generations. Yet materials are often damaged or deteriorate for varied reasons.
The NDL is taking countermeasures such as the special treatment of acidic paper and the duplication of materials into microfilms and other different media. The Preservation Division restores damaged materials. The NDL has been urging publishers to use acid-free paper.
Cataloging, Providing Bibliographic Data and Indexes
The National Diet Library completes bibliographic cataloging for collected materials and provides various types of bibliographic data. The Library's catalogs are accessible via the Internet (National Diet Library Online Public Access Catalog).
Major Bibliographies and Indexes
The NDL provides the National Bibliography on the web to provide prompt and precise bibliographic data on the newly collected Japanese publications inside and outside Japan. The data in the National Bibliography are processed into a database, recorded on the JAPAN/MARC CD-ROM or DVD-ROM discs, and distributed to libraries for cataloging.
The NDL compiles the Japanese Periodical Index for articles in major Japanese periodicals since 1948. This index is available via the Internet and distributed with CD-R or DVD-ROM format.
"Index to Japanese Laws, Regulations and Bills"
Index of laws and regulations of Japan since 1867 according to subject, year, and title. Bills and treaties before the Diet since 1947 are also included, linked with relevant part of Full-text Database System for the Minutes of the Diet.