Individual-item information management device and method

In an assembled product, a decrease in reading efficiency is avoided from being deteriorated by reading the electronic tags of the parts and the assembled product, registering their configuration information (1230), and by placing read restriction on the electronic tags of the parts. For this purpose, manufacturing instruction information (1210), used for assembling parts into an assembled product, is used. When replaced, the electronic tags of the assembled product are read, read restriction is removed from the assembled product, the electronic tag is read, the electronic tag of a new part to be installed is read, read restriction is placed on the electronic tag, and the configuration information (1230) is updated. An invalid part replacement is detected by comparing the configuration information (1230).