A contact state of a finger with respect to a first displayed object is detected. In response to detecting a double-click operation on the first displayed object at a first position in a depthwise direction, the first displayed object is moved onto a surface of a display screen of a three-dimensional (3-D) display. In response to detecting that the finger has moved from the contact state to a proximity state with respect to the first displayed object, a display position of the first displayed object is changed from the surface of the display screen to a depth position at which a second object is displayed at a nearest side in the depthwise direction among displayed objects. The second object remains displayed at the depth position beside the first object.