A sensor magnet holder is mounted on a motor shaft, and a sensor magnet is provided relative to a magnetic induction sensor on the non-moving side for obtaining a signal indicative of a rotational position of the motor shaft. The sensor magnet holder integrally forms a cylindrical portion, a flange portion of a terminal end of the cylindrical portion having a large diameter, a magnet rear end holding portion of the other terminal end of the cylindrical portion and a plurality of snap fit board portions. A shaft press fit portion is formed on an internal diameter of the flange portion. The plural snap fit board portions extend from the cylindrical portion in an axial direction of the motor shaft. A magnet front end holding portion is formed at an extending tip over an outer diameter surface of each of the snap fit board portions. Each of the flexible snap fit board portions snuggly contacts the inner flat surface of the sensor magnet while the sensor magnet is held between said magnet rear end holding portion and said magnet front end holding portion.