The present invention relates to an optical character recognition device (OCR) for reading a form provided with character frames in reading fields, into which a user fills each character. Characteristic vectors are extracted from the character images of each frame. A number of characters decision unit 16, into which the characteristic vectors are input, decides the number of characters filled in one of the character frames. A character separation unit 18 separates each of characters from the character image based on the number of characters decided by the decision unit 16. The character recognition unit 20 then recognizes each of the character. The OCR according o the present invention is able to read the form correctly, in which a plurality of characters are filled in one of the frames.