Ring-shaped wireless input device with scroll function

A wireless input device of a ring shape having a scrolling function which is worn on fingers is provided to allow a user to wear the wireless input device on the fingers and apply the device to various electronic devices. A housing(110) has the ring shape. A wheel(120) is pivotally installed on the housing. A first sensor has the first and the second sections. The first and the second section are reciprocally arranged according to the circumference of wheel. The second sensor is fixed within the housing and is arranged in the first sensor. The first section has the conductivity. The second section has the insulating property. A pair of contact assistant is the switch-on or the switched-off by contacting the first or the second section.