Potentiometer

A non-contact type potentiometer with high resolution of rotation amount detection applicable to endlessly multiple rotations. The potentiometer has an endlessly rotatable first shaft, a first detection unit that magnetically detects a rotation angle of the first shaft in a non-contact manner, an endlessly rotatable second shaft, a second detection unit that magnetically detects a rotation angle of the second shaft in a non-contact manner, a transmission unit that decreases the speed of the rotation of the first shaft and transmits the rotation to the second shaft, and an output unit that outputs an electric signal proportional to a rotation amount of the first shaft based on detection signals from the first detection unit and the second detection unit.