PURPOSE: To improve recognition performance by enabling a same recognition result to be obtained for characters of a same form in the same document even when collation with a word dictionary, etc., is performed.

CONSTITUTION: A recognition character in a character reading part 3 is corrected by collating with the word dictionary 7 in the unit of word, while, classification at every character of a same form is performed. Processing to obtain a same recognition result for the character of the same form is performed by reflecting the classification result of the character of a same form on character recognition by collation with the word dictionary. Thereby, it is possible to correct an erroneously recognized character by utilizing the result of the collation with another word for an unknown word.