1. A target-image search apparatus comprising: a first target-image detecting device for detecting a target image from a first subject image among a plurality of frames of subject images obtained by sensing the image of a subject successively; a detection-angle deciding device for deciding a detection angle of the target image based upon a relative angle of rotation between the target image detected by said first target-image detecting device and the first subject image; and a second target-image detecting device for detecting the target image, which has an angle based upon the detection angle decided by said detection-angle deciding device, from a second subject image different from the first subject image among the plurality of frames of subject images.