Rotational angle measurement apparatus measuring magnetic-field angle or rotational angle with sufficient accuracy wherein a non-magnetic conductor is arranged in the vicinity of the magnetic flux generator or the magnetic sensor, even when the magnetic flux generator rotates at high speed. The rotational angle measurement apparatus is configured with a magnetic sensor 70 which responds to a magnetic-field angle and a detection unit 302 which inputs an output of the magnetic sensor. The rotational angle measurement apparatus is employed with a rotatable body 121 provided with a magnetic flux generator 202. The output of the magnetic sensor is a raw-angle signal set 155 corresponding to the magnetic-field angle. The detection unit outputs a corrected angle after a non-magnetic conductor in the vicinity of the magnetic sensor is corrected, using a correction value outputted by a correction function with rotational velocity of the rotatable body as an argument.