Abstract: An accelerator position sensor urges a rotary member 2into rotation relative to a fixed member 1 fixed on the side of a vehicle body in a direction of a returning operation of an accelerator pedal by torque of a torsion spring 3, and detects the angle of rotation of the rotary member 2 in a sensor unit 4 thereof. In the accelerator position sensor, a cylindrical resin member 6 is disposed between a boss 1a of the fixed member 1 and the torsion spring 3 so as to be pressed against the boss 1a by a reaction of the torque of the torsion spring 3 to create sliding resistance to the boss 1a during rotation of the rotary member 2, in order that the pressing force characteristic of the accelerator pedal exhibits sufficient hysteresis between pressing and returning operations.