An accelerator position sensor (APS) includes a transmitting coil generating a magnetic field, a coupler controlling the magnetic field generated from the transmitting coil, a receiving coil receiving the magnetic field generated from the transmitting coil to generate a predetermined frequency, and a signal processor calculating rotation information of the coupler using the frequency received from the receiving coil and outputting displacement values of an accelerator pedal. With the APS, a guarantee signal can be generated only through the receiving coil and precise measuring values can be achieved.