Disclosed is an alphabetic character input device which includes a key input section composed of a first key group having input keys mapped with first half patterns of certain alphabetic characters which are divided into a pair of half patterns and a second key group having input keys mapped with second half patterns of said certain alphabetic characters, the other undivided alphabetic characters being mapped on the input keys of either the first key group or the second key group; a memory for storing a table that maps the input keys of the first and second key groups with the first and second half patterns of said certain alphabetic characters and said other alphabetic characters; and a control section that recognizes a key mapped with the alphabetic character is pressed and combines a first half pattern with a second half pattern when keys mapped with first second half patterns are pressed in sequence, thereby recognizing the combined patterns as a single alphabetic character. An alphabetic character can be inputted by one or two keystrokes. Certain alphabetic character are each divided into a pair of half patterns, i.e., a first half pattern and a second half pattern, which are intuitively associated with a complete alphabetic character. Thus, the character input device enables the user to easily and rapidly input alphabetic characters with fewer keystrokes.