PURPOSE: To input characters efficiently, by shifting a character group hitherto imputted by one digit when a specific key is depressed and inputting a small character of the next character key in the least significant digit.

CONSTITUTION: "1" is outputted when a small character designating key KEY1 is depressed, and a binary signal is outputted to a terminal B when a key constituting a character key group KEY2 is depressed, and keys KEY3 are composed of a retrieval key and an erase key. When the key KEY2 is depressed for the purpose of inputting KANA (Japanese syllabary) character "to", the key code is stored in the least significant digit LSD of a register REG through an AND circuit G2 and an OR circuit G4. Next, when the KEY1 is depressed, an FF F1 is set, and "to" is shifted to the left by one digit, and the next input character is inputted in the least significant digit of the register REG.