A rotation angle detecting unit includes a pedal arm rotated by the pedal force transmitted from an accelerator pedal, an urging device urging the pedal arm in an opposite direction from a direction, in which pedal force is applied to the pedal arm, a pedal rotor engaging the pedal arm to transmit urging force of the urging device to the pedal arm, and a rotation angle detecting device detecting the rotation angle of the accelerator pedal. The rotation angle detecting device includes a movable part attached to the pedal rotor and thereby displaced together with the pedal rotor, and a stator that outputs an electric signal, which is associated with a rotational position of the pedal rotor due to one of magnetic and electric interactions with the movable part.