A terminal, comprising: a) a camera unit configured to capture an image; b) an input unit configured to input a user's input associated with an instant messaging function for transmitting and receiving instant messages to and from one or more other terminals; c) a display unit configured to output a user interface screen according to execution of the instant messaging function, the user interface screen including a dialog window in which the instant messages transmitted to or received from the one or more other terminals are displayed; d) a control unit functionally connected to the camera unit, the input unit, and the display unit, e) wherein the control unit is configured to control the camera unit to be activated in response to a first user' s input for changing a background screen of the dialog window, and to control the activated camera unit to capture the image; f) wherein the control unit is further configured to control the display unit to display the captured image in the background screen; g) wherein when a second user' s input for transmission of the image displayed in the background screen is recognized, the control unit is further configured to transmit the image displayed in the background screen to the one or more other terminals; h) wherein the second user' s input is an input of a predetermined word entered in the dialog window by manipulating a keypad display unit; and i) wherein when the predetermined word is entered in the dialog window, the control unit recognizes the predetermined word as a user command rather than as the instant message to be transmitted to the one or more other terminals. a) a camera unit configured to capture an image; b) an input unit configured to input a user's input associated with an instant messaging function for transmitting and receiving instant messages to and from one or more other terminals; c) a display unit configured to output a user interface screen according to execution of the instant messaging function, the user interface screen including a dialog window in which the instant messages transmitted to or received from the one or more other terminals are displayed; d) a control unit functionally connected to the camera unit, the input unit, and the display unit, e) wherein the control unit is configured to control the camera unit to be activated in response to a first user' s input for changing a background screen of the dialog window, and to control the activated camera unit to capture the image; f) wherein the control unit is further configured to control the display unit to display the captured image in the background screen; g) wherein when a second user' s input for transmission of the image displayed in the background screen is recognized, the control unit is further configured to transmit the image displayed in the background screen to the one or more other terminals; h) wherein the second user' s input is an input of a predetermined word entered in the dialog window by manipulating a keypad display unit; and i) wherein when the predetermined word is entered in the dialog window, the control unit recognizes the predetermined word as a user command rather than as the instant message to be transmitted to the one or more other terminals.