A method of controlling a user terminal apparatus having first and second user modes, the method comprising: displaying a locking screen; in response to receiving, on the locking screen, a first unlocking control input corresponding to the first user mode, reconstituting the screen based on use authority information corresponding to the first user mode and displaying the reconstituted screen including a first plurality of icons representing applications executable within the first user mode based on the use authority information; in response to receiving, on the locking screen, a second unlocking control input corresponding to the second user mode, reconstituting the screen based on use authority information corresponding to the second user mode and displaying the reconstituted screen including a second plurality of icons representing applications executable within the second user mode based on the use authority information, wherein the first and second unlocking control inputs represent authentication inputs; and wherein the method further comprises: displaying a first icon indicating the first user mode while the user terminal apparatus operates in the first user mode, and based on the first icon being selected, displaying a first lock screen for mode conversion on a display screen, displaying a second icon indicating the second user mode while the user terminal apparatus operates in the second user mode, and based on the second icon being selected, displaying a second lock screen for mode conversion on the display screen, the first lock screen being different from the second lock screen, and wherein each of the first lock screen and the second lock screen includes at least one UI element for receiving one of the first or second unlocking control inputs, and in response to receiving the first unlocking control input to the second lock screen, reconstituting the screen based on use authority information corresponding to the first user mode, and displaying the reconstituted screen in the first user mode; and in response to receiving the second unlocking control input to the first lock screen, reconstituting the screen based on use authority information corresponding to the second user mode; and displaying the reconstituted screen in the second user mode. displaying a locking screen; in response to receiving, on the locking screen, a first unlocking control input corresponding to the first user mode, reconstituting the screen based on use authority information corresponding to the first user mode and displaying the reconstituted screen including a first plurality of icons representing applications executable within the first user mode based on the use authority information; in response to receiving, on the locking screen, a second unlocking control input corresponding to the second user mode, reconstituting the screen based on use authority information corresponding to the second user mode and displaying the reconstituted screen including a second plurality of icons representing applications executable within the second user mode based on the use authority information, wherein the first and second unlocking control inputs represent authentication inputs; and wherein the method further comprises: displaying a first icon indicating the first user mode while the user terminal apparatus operates in the first user mode, and based on the first icon being selected, displaying a first lock screen for mode conversion on a display screen, displaying a second icon indicating the second user mode while the user terminal apparatus operates in the second user mode, and based on the second icon being selected, displaying a second lock screen for mode conversion on the display screen, the first lock screen being different from the second lock screen, and wherein each of the first lock screen and the second lock screen includes at least one UI element for receiving one of the first or second unlocking control inputs, and in response to receiving the first unlocking control input to the second lock screen, reconstituting the screen based on use authority information corresponding to the first user mode, and displaying the reconstituted screen in the first user mode; and in response to receiving the second unlocking control input to the first lock screen, reconstituting the screen based on use authority information corresponding to the second user mode; and displaying the reconstituted screen in the second user mode. displaying a first icon indicating the first user mode while the user terminal apparatus operates in the first user mode, and based on the first icon being selected, displaying a first lock screen for mode conversion on a display screen, displaying a second icon indicating the second user mode while the user terminal apparatus operates in the second user mode, and based on the second icon being selected, displaying a second lock screen for mode conversion on the display screen, the first lock screen being different from the second lock screen, and wherein each of the first lock screen and the second lock screen includes at least one UI element for receiving one of the first or second unlocking control inputs, and in response to receiving the first unlocking control input to the second lock screen, reconstituting the screen based on use authority information corresponding to the first user mode, and displaying the reconstituted screen in the first user mode; and in response to receiving the second unlocking control input to the first lock screen, reconstituting the screen based on use authority information corresponding to the second user mode; and displaying the reconstituted screen in the second user mode.