Abstract: Provided is a mouse including: a ball body; and a mouse body including a receiving part in which the ball body having a spherical shape is rollably received. The receiving part includes: a receiving recess part opening outward and formed to be recessed inward to receive the ball body therein; and a support member disposed on the receiving recess part for supporting the ball body received in the receiving recess part, and the support member is configured to be attachable to and detachable from the receiving recess part.

Abstract: A moving position detector suitable for use as a lightweight, thin mouse. Rotations generated by virtue of frictional forces generated between a bottom of a rotating body and a floor surface are detected by a rotation detecting means as the number of rotations of a rotary encoder portion and converted into an output signal corresponding to the signal from the encoder portion for output to an output means for input into a computer. The rotating body has a pressurizing point for applying loads by gravity or a mechanical element to positions other than a center on the bottom in a direction normal to a moving direction of a mouse relative to the shaft.