An input device separated from a display unit for switchably displaying images hierarchized in hierarchy levels and configured to input a finger operation of a user to an operation surface to operate the images is provided. The input device includes a detector for detecting an operation state of the finger to the operation surface at a time of the finger operation and a controller for, when determining that the operation state detected by the detector is a proximity state, reducing sharpness of at least part of the image displayed on the display unit as compared with when determining that the operation state is a contact state.