A user interface system having an improved usability is provided. The user interface system comprises: an operation section (21) an operation section for receiving an instruction inputted by a user; a finger position detecting section (32) for detecting a group of first coordinate values, each indicating a current position of a fingertip, of a user, which is placed on an operation surface of the operation section; a component storing section (4) for storing component data representing a GUI (Graphical User Interface) component; an assignment section (34) for uniquely assigning the component data stored in the component storing section to each of the first coordinate values detected by the finger position detecting section (32); an image generating section (35) for generating a GUI image representing a user interface in which the GUI component represented by the component data stored in the component storing section (4) is uniquely associated with each of the first coordinate values detected by the finger position detecting section (32), in accordance with an assignment performed by the assignment section; and a display controlling section (36) for displaying the GUI image generated by the image generating section (35) on a display screen.