An apparatus for providing a virtual graffiti function, comprising: a touch-screen display (400, 500) for displaying information on its screen, and at the same time receiving user-entry data created by a user touching the screen; and a controller connected to the touch-screen display (400, 500), which overlaps a graffiti screen image with a main screen image in a virtual graffiti area for providing a portion of the screen with virtual graffiti, the controller being adapted to classify the user-entry data created by the user touching the virtual graffiti area into application execution entry data corresponding to the main screen image and graffiti entry data corresponding to the graffiti screen image according to the touched position and a fixed touch time of the user touching in which the user touches the virtual graffiti area of the screen, and to process the classified user-entry data according to the classification, wherein the graffiti screen image is overlapped with the main screen image in said virtual graffiti area by translucently displaying said virtual graffiti area on the main screen image for displaying both information located in the main screen image and information located in the virtual graffiti area at the same time, wherein, for classifying the user-entry data created by the user touching the virtual graffiti area, the controller is adapted to: determine the user-entry data as an application execution entry data corresponding to an application icon included in the main screen image, if the fixed touch time of the user touching is longer than a predetermined time; determine the user-entry data as a graffiti entry data, if the fixed touch time of the user touching is equal to or shorter than the predetermined time and the touched position is in a graffiti input area in the virtual graffiti area; and determine the user-entry data as an application execution entry data corresponding to a graffiti icon included in the graffiti screen image, if the fixed touch time of the user touching is equal to or shorter than the predetermined time and the touched position is outside of the graffiti input area in the virtual graffiti area a touch-screen display (400, 500) for displaying information on its screen, and at the same time receiving user-entry data created by a user touching the screen; and a controller connected to the touch-screen display (400, 500), which overlaps a graffiti screen image with a main screen image in a virtual graffiti area for providing a portion of the screen with virtual graffiti, the controller being adapted to classify the user-entry data created by the user touching the virtual graffiti area into application execution entry data corresponding to the main screen image and graffiti entry data corresponding to the graffiti screen image according to the touched position and a fixed touch time of the user touching in which the user touches the virtual graffiti area of the screen, and to process the classified user-entry data according to the classification, wherein the graffiti screen image is overlapped with the main screen image in said virtual graffiti area by translucently displaying said virtual graffiti area on the main screen image for displaying both information located in the main screen image and information located in the virtual graffiti area at the same time, wherein, for classifying the user-entry data created by the user touching the virtual graffiti area, the controller is adapted to: determine the user-entry data as an application execution entry data corresponding to an application icon included in the main screen image, if the fixed touch time of the user touching is longer than a predetermined time; determine the user-entry data as a graffiti entry data, if the fixed touch time of the user touching is equal to or shorter than the predetermined time and the touched position is in a graffiti input area in the virtual graffiti area; and determine the user-entry data as an application execution entry data corresponding to a graffiti icon included in the graffiti screen image, if the fixed touch time of the user touching is equal to or shorter than the predetermined time and the touched position is outside of the graffiti input area in the virtual graffiti area determine the user-entry data as an application execution entry data corresponding to an application icon included in the main screen image, if the fixed touch time of the user touching is longer than a predetermined time; determine the user-entry data as a graffiti entry data, if the fixed touch time of the user touching is equal to or shorter than the predetermined time and the touched position is in a graffiti input area in the virtual graffiti area; and determine the user-entry data as an application execution entry data corresponding to a graffiti icon included in the graffiti screen image, if the fixed touch time of the user touching is equal to or shorter than the predetermined time and the touched position is outside of the graffiti input area in the virtual graffiti area