To easily distribute discontinued products and maintenance products necessary for purchasers when the products are requested by controlling the inventory of the manufacture-stopped products and maintenance products in a plurality of parts and material traders in a manufacturable period of the discontinued products and in a maintainable period of the maintenance products.

An inventory management server 2 solely implements the retrieval service of the inventory, the replacement information of the discontinued products and maintenance products such as the parts and the materials from terminals 1 of purchasers via the Internet 100, the registration service of the information on the discontinued products and the maintenance products from terminals 4 of manufacturers, and the collective storage and delivery control of articles to be ordered from the terminals 1 of the purchasers.