There is a conventional input device wherein a blind operation is easy because a touch panel type operation unit and a display unit are separately arranged at locations distant from each other, but such a conventional input device requires a camera for photographing a user's hand on the operation unit, and image processing for converting the photographed image of the hand and combining the image on the display unit, and thus, simplification of the processing method has been desired. Further, reducing the number of components used for such a device has been desired. Disclosed are an input device using a touch panel and an input method thereof, wherein the input device (1) which uses a touch panel is configured by an optical touch panel (3) provided with a touch-type touch panel (2), a retroreflection film (31) covering a surface of the touch-type touch panel (2), and a pair of detection units (34) located on the upper portions of the opposite ends of a side of the touch-type touch panel (2), and wherein two types of detection which are recognition of the shape of the operating body and detection of coordinate positions can be performed by the optical touch panel.