A position detection apparatus for detecting a position of an object includes a video image producer which produces a video image signal representing the object image. The video image signal is divided into first and second level portions by an edge point. An edge point detector detects the edge point where said level difference is greater than a threshold level. A window filter is provided to increase this level difference to a level greater than a threshold so that the edge point detector can detect the edge point even when the level difference is smaller than the threshold level. A shape detector detects the position of the object based on thus detected edge point.