An apparatus for inputting characters in a terminal, comprising: a touch screen for displaying a basic key set and an extended key set (502, 602, 702), the basic key set including consonant keys and the extended key set including character keys corresponding to characters combinable with a consonant corresponding to a consonant key input from the basic key set; and a controller configured to: control the touch screen to display the basic key set, in response to a touch on a consonant key, control the touch screen to display a first consonant character corresponding to the touched consonant key on a display and to display a pop-up window over the touched consonant key, the pop-up window comprising an extended key set including a key corresponding to the touched consonant key and character keys combinable with the touched consonant key, and in response to dragging the touch, display a second character on the display corresponding to one of the character keys of the extended key set, wherein the dragging the touch is a drag and drop movement from the touched consonant key to the one of the character keys of the extended key set, and characterized in that the controller is further configured to simultaneously display two consonant characters corresponding to a touched consonant key by making a dragging movement corresponding to dragging the touched consonant key in a predetermined area of the touched consonant key without taking off the touch for a predetermined time, and display a further character corresponding to a character key input from the extended key set by making a further drag and drop movement corresponding to dragging from the touched consonant key to the character key of the extended key set after the said dragging movement. a touch screen for displaying a basic key set and an extended key set (502, 602, 702), the basic key set including consonant keys and the extended key set including character keys corresponding to characters combinable with a consonant corresponding to a consonant key input from the basic key set; and a controller configured to: control the touch screen to display the basic key set, in response to a touch on a consonant key, control the touch screen to display a first consonant character corresponding to the touched consonant key on a display and to display a pop-up window over the touched consonant key, the pop-up window comprising an extended key set including a key corresponding to the touched consonant key and character keys combinable with the touched consonant key, and in response to dragging the touch, display a second character on the display corresponding to one of the character keys of the extended key set, wherein the dragging the touch is a drag and drop movement from the touched consonant key to the one of the character keys of the extended key set, and characterized in that the controller is further configured to simultaneously display two consonant characters corresponding to a touched consonant key by making a dragging movement corresponding to dragging the touched consonant key in a predetermined area of the touched consonant key without taking off the touch for a predetermined time, and display a further character corresponding to a character key input from the extended key set by making a further drag and drop movement corresponding to dragging from the touched consonant key to the character key of the extended key set after the said dragging movement. control the touch screen to display the basic key set, in response to a touch on a consonant key, control the touch screen to display a first consonant character corresponding to the touched consonant key on a display and to display a pop-up window over the touched consonant key, the pop-up window comprising an extended key set including a key corresponding to the touched consonant key and character keys combinable with the touched consonant key, and in response to dragging the touch, display a second character on the display corresponding to one of the character keys of the extended key set, wherein the dragging the touch is a drag and drop movement from the touched consonant key to the one of the character keys of the extended key set, and characterized in that the controller is further configured to simultaneously display two consonant characters corresponding to a touched consonant key by making a dragging movement corresponding to dragging the touched consonant key in a predetermined area of the touched consonant key without taking off the touch for a predetermined time, and display a further character corresponding to a character key input from the extended key set by making a further drag and drop movement corresponding to dragging from the touched consonant key to the character key of the extended key set after the said dragging movement.