1. A tracking apparatus that tracks a face position in a dynamic picture image, the tracking apparatus comprising: a face detection device, which detects a face from the image; a storage device in which ambient information obtained from a region determined by a relative positional relationship with the face position is stored in association with a face position detected by the face detection device; and an estimation device, which determines a plurality of position candidates of a current face based on a most recently detected face position instead of the face detection by the face detection device, the estimation device obtaining a plurality of pieces of ambient information corresponding to the position candidates, and determining the current face position based on the obtained position candidate in which the ambient information being most similar to the ambient information associated with the most recently detected face position is obtained.