A multilingual character input device, comprising: a keyboard unit for displaying a keyboard layout of a plurality of languages, wherein the keyboard layout comprises keys of a numeric/symbol keys section, F keys section, character keys section of each language, functional keys section and a language conversion key; a display unit for displaying a character input by character keys on a display; a storage unit for storing characters, a list of data and a program; and, a control unit for controlling the keyboard unit, the display unit and the storage unit, wherein the numeric/symbol keys section comprises numbers disposed at a lower part of the numeric/symbol keys and symbols disposed at an upper part of the numeric/symbol keys; wherein the F keys section is disposed below the numeric/symbol keys section and comprises an F+α key and multiple F keys displaying at least one of F functions, characters and preset functions; wherein the character keys section is disposed below the F keys section, comprises character phonemes keys comprising basic phoneme keys and variant phonemes keys, wherein the keyboard layout of one language is converted into the keyboard layout of another language by pressing the language conversion key of the keyboard unit, each time when the language conversion key is pressed, the control unit is configured so that characters corresponding to selected languages are converted in a predetermined order and displayed on the keyboard layout of the keyboard unit, wherein when the F+α key is not pressed as the F+α key is not activated, the F keys section is configured to display an original set functions such that the at least one of F functions, the characters and the preset functions are displayed on the multiple F keys, and wherein each time when the F+α key is pressed, the control unit is configured to convert sequentially characters/functions so that the multiple F keys display another set of keys comprising another variant characters, special characters or symbols of the at least one of F functions, the preset function, and the characters. a keyboard unit for displaying a keyboard layout of a plurality of languages, wherein the keyboard layout comprises keys of a numeric/symbol keys section, F keys section, character keys section of each language, functional keys section and a language conversion key; a display unit for displaying a character input by character keys on a display; a storage unit for storing characters, a list of data and a program; and, a control unit for controlling the keyboard unit, the display unit and the storage unit, wherein the numeric/symbol keys section comprises numbers disposed at a lower part of the numeric/symbol keys and symbols disposed at an upper part of the numeric/symbol keys; wherein the F keys section is disposed below the numeric/symbol keys section and comprises an F+α key and multiple F keys displaying at least one of F functions, characters and preset functions; wherein the character keys section is disposed below the F keys section, comprises character phonemes keys comprising basic phoneme keys and variant phonemes keys, wherein the keyboard layout of one language is converted into the keyboard layout of another language by pressing the language conversion key of the keyboard unit, each time when the language conversion key is pressed, the control unit is configured so that characters corresponding to selected languages are converted in a predetermined order and displayed on the keyboard layout of the keyboard unit, wherein when the F+α key is not pressed as the F+α key is not activated, the F keys section is configured to display an original set functions such that the at least one of F functions, the characters and the preset functions are displayed on the multiple F keys, and wherein each time when the F+α key is pressed, the control unit is configured to convert sequentially characters/functions so that the multiple F keys display another set of keys comprising another variant characters, special characters or symbols of the at least one of F functions, the preset function, and the characters.