To generate an address table capable of analyzing an address, even in an input with fluctuation of a plurality of character strings.

A writing of a formal address data of the input character string is correlated with its reading, using a character information storage means registered with information of the presence of the reading in every one character and the writing corresponding thereto, and a different writing address is derived to be registered in an address table, referring to a derivation rule storage means stored with a derivation rule when no writing for the reading exists, a derivation rule for the writing and a derivation rule for the writing and the reading.