A mobile terminal comprising: a display unit; a user input unit configured to receive an input of a command from a user; a microphone configured to converting a speech signal to an electric signal; a communication module (110; 170) configured to transmit a signal to and receive a signal from an external device by wire and/or wirelessly; and a controller, wherein the controller is configured to: connect to at least one external device (410; 430; 450; 470) via the communication module (110; 170), execute a speech recognition mode, receive a first speech signal corresponding to a user's speech command for controlling the at least one external device via the microphone, display a prescribed graphic user interface on the display unit according to the speech command recognized with the first speech signal, wherein the speech command includes a target content, a source device having the target content, an operation to be performed on the target content and a target device to perform the operation, and wherein each of the source device and the target device is selected to be one of the mobile terminal and the connected at least one external device (410; 430; 450; 470), wherein the GUI contains elements that display information corresponding to the recognized target content, the source device having the target content, the operation to be performed on the target content and the target device to perform the operation, and receive a second speech signal to modify the recognized target content by a recognition of the second speech signal into a new target content, characterized in that the controller determines whether the operation to be performed on the new target content is executable by the target device and wherein if the operation is not executable as a result of the determination, a prescribed visual effect is given in the vicinity of the displayed information corresponding to the recognized target device to indicate that the operation command for the new target content is inexecutable. a display unit; a user input unit configured to receive an input of a command from a user; a microphone configured to converting a speech signal to an electric signal; a communication module (110; 170) configured to transmit a signal to and receive a signal from an external device by wire and/or wirelessly; and a controller, wherein the controller is configured to: connect to at least one external device (410; 430; 450; 470) via the communication module (110; 170), execute a speech recognition mode, receive a first speech signal corresponding to a user's speech command for controlling the at least one external device via the microphone, display a prescribed graphic user interface on the display unit according to the speech command recognized with the first speech signal, wherein the speech command includes a target content, a source device having the target content, an operation to be performed on the target content and a target device to perform the operation, and wherein each of the source device and the target device is selected to be one of the mobile terminal and the connected at least one external device (410; 430; 450; 470), wherein the GUI contains elements that display information corresponding to the recognized target content, the source device having the target content, the operation to be performed on the target content and the target device to perform the operation, and receive a second speech signal to modify the recognized target content by a recognition of the second speech signal into a new target content, characterized in that the controller determines whether the operation to be performed on the new target content is executable by the target device and wherein if the operation is not executable as a result of the determination, a prescribed visual effect is given in the vicinity of the displayed information corresponding to the recognized target device to indicate that the operation command for the new target content is inexecutable. connect to at least one external device (410; 430; 450; 470) via the communication module (110; 170), execute a speech recognition mode, receive a first speech signal corresponding to a user's speech command for controlling the at least one external device via the microphone, display a prescribed graphic user interface on the display unit according to the speech command recognized with the first speech signal, wherein the speech command includes a target content, a source device having the target content, an operation to be performed on the target content and a target device to perform the operation, and wherein each of the source device and the target device is selected to be one of the mobile terminal and the connected at least one external device (410; 430; 450; 470), wherein the GUI contains elements that display information corresponding to the recognized target content, the source device having the target content, the operation to be performed on the target content and the target device to perform the operation, and receive a second speech signal to modify the recognized target content by a recognition of the second speech signal into a new target content, characterized in that the controller determines whether the operation to be performed on the new target content is executable by the target device and wherein if the operation is not executable as a result of the determination, a prescribed visual effect is given in the vicinity of the displayed information corresponding to the recognized target device to indicate that the operation command for the new target content is inexecutable.