PURPOSE: To ensure an effective input of a sentence in a short time, by operating a HIRAGANA (Japanese syllabary) key switch for HIRAGANA letters and operating twice the said key switch for Chinese characters, respectively.

CONSTITUTION: An input mechanism 5 includes a keyboard unit containing a number of key switches 6 puls an arithmetic storage device 9 which stores an key input with the operation of the switches 6 and delivers it to an output mechanism 8 with one of its ends connected to the switches 6 and with the other end connected to the mechanism 8, respectively. The device 9 includes an encoder 9B that is connected to a CPU9A which converts the code for the signal sent from HIRAGANA key switches 6A Chinese character mode designation keyes 6B, English capital/numeric changeover key switches 6C, English small letter/code changeover key switches 6D and KATAKANA (square Japanese syllabary) letter changeover key switches 6E each plus an output key data processing part OUT.