An aspect of the invention is an information terminal device includes a widget management unit for managing execution of a widget being a monofunctional program for performing display on the display part of a display device. The widget management unit includes a policy determination unit for determining the operation policy, including operation restriction and priority, concerning a display state at the display device in the widget, and a reliability determining unit for determining the reliability representing the reliability of the widget in the widget. When the state of the movement calculated by a navigation unit becomes a preset state, the widget management unit regulates the display state of the widget according to the operation restriction and the reliability, and performs display, while preferentially displaying guidance state and positional information calculated by the navigation unit.