Abstract: Input according to Pin Yin notation and input according to Zhu Yin notation are allowed. Input data in the Pin Yin notation and input data in the Zhu Yin notation are respectively converted into corresponding Yin codes using a Pin Yin/Yin code conversion table and a Zhu Yin/Yin code conversion table. A dictionary stores a Chinese character code (corresponding to a word) in correspondence with an Yin code sequence. An input Yin code sequence is created from the input data. An Yin code in the input Yin code sequence and an Yin code in the Yin code sequence in the dictionary are compared with each other through a filter for masking a predetermined bit of the Yin code. A Chinese character code corresponding to Yin code sequences which coincide with each other by the comparison is read out from the dictionary, and a word (a Chinese character) corresponding to the Chinese character code is displayed.