1. A face tracking device for tracking an orientation of a person's face with using a cylindrical head model, the face tracking device comprising: an image means for continuously shooting the person's face and for obtaining a first image data based on a shot of the person's face; an extraction means for extracting a second image data from the first image data, the second image data corresponding to a facial area of the person's face; a determination means for determining whether the second image is usable as an initial value required for the cylindrical head model; and a face orientation detection means for detecting the orientation of the person's face with using the cylindrical head model and with using the initial value determined to be usable by the determination means.