A guide robot can include a travel part to move the guide robot, a touch screen and a camera, a sensor to detect an approach of a user, and a voice reception part to receive a voice. The guide robot further includes a controller to display at least one digital signage while the guide robot is traveling, in response to detecting the approach of the user, stop the traveling of the guide robot and transition the camera from a deactivated state to an activated state, and detect a face and a face angle of the user. Also, in response to determining that the user intends to use the guide robot, the controller can trigger a voice conversation mode by activating the voice reception part, stopping the display of the at least one digital signage and outputting usage guide information for the voice conversation mode.