To provide an input device for giving a sense of operation close to that of a track ball whose operability is excellent without generating any failure specific to a mechanical type.

At the time of operating the surface (operation face) of a dome- shaped cover 5 with the finger or the like, an image on the surface of the cover 5 is captured through an optical element 6 by an inside image pickup element 4. A video signal captured by the image pickup element 4 is converted into coordinate information by an image processing means 10, and outputted to an external device main body, and a cursor on a display is moved. This optical input device is configured as an optical type so that any failure specific to a mechanical type can be prevented from being generated. Also, the operation face is shaped like a dome so that the optical input device can be operated with a sense of operation close to that of a track ball, and that the operability can be improved.