PURPOSE: To correct easily a character which is inputted when fingers are shifted from home postions, by providing a circuit which converts code signals corresponding to keys of a specific key group to code signals corresponding to keys left adjacent to to respective keys.

CONSTITUTION: Many character keys and function keys including a conversion key are provided on a keyboard 1; and when a character key is depressed, a corresponding code signal is inputted to a controlling circuit 6, and the circuit 6 stores it in a buffer memory 7 and outputs it to a display 8 to display a character pattern of a memory 8a corresponding to the code signal on the display 8. When the conversion key is depressed in case that a character key is depressed with fingers shifted right from home positions by one key, a conversion code is inputted to a code signal converting circuit 6a, and the circuit 6a converts the code to a code corresponding to a character key left adjacent to the depressed character key, and a corresponding character pattern of the memory 8a is displayed, and the converted code is stored in the memory 7. Thus, an erroneous inputted character is corrected, and the correct character is outputted to a printer 10.