PURPOSE: To prevent a trouble to attach a ruby on a document in advance by obtaining the ruby by dividing a character string into every character string of one unit, and retrieving a corresponding dictionary, respectively.

CONSTITUTION: The device is equipped with a dictionary 8 retrieved at every unit of character string by conforming the character string including a KANJI (Chinese character) to the ruby and divided in plural hierarchical structure, and a division processing part 6 which performs division at every unit of character string corresponding to the hierarchical structure of the dictionary. After the character string including the KANJI is read, the character string is divided into every unit of character string first, and a dictionary retrieval part 7 retrieves the dictionary 8 at every unit of character string, then, obtains the ruby. A processing to obtain the ruby for an unrecognized character or the character string not being hit by retrieval is interrupted. In such a way, the trouble to attach the ruby on the document can be eliminated, and fast retrieval for the dictionary including a comparatively large amount of data such as an address directory can be performed by hierarchical structure.