To provide a position detecting device which is hard to give incompatible feeling to operation feeling.

A position detecting device 1 comprises a portion 4 to be detected which rotates on the basis of the rotating action of a handle grip 3 provided on a handle bar 2, a detecting portion 5 for detecting the portion 4 to be detected, and a case 6 for storing the portion 4 to be detected and the detecting portion 5. The position detecting device 1 comprises a holder member 4a constituting the portion 4 to be detected, and a supporting member 7 for rotatably supporting the holder member 4a and holding the detecting portion 5. The holder member 4a is provided with a first sliding portion 4d sliding with the supporting member 7, and the supporting member 7 is provided with a second sliding portion 76 sliding with the first sliding portion 4d. The holder member 4a is provided with a cover portion 4e for covering a sliding part between the first sliding portion 4d and the second sliding portion 76.