The present invention relates to a target image detecting apparatus and a method thereof. According to the present invention, the target video detecting apparatus calculates a video index for each frame of an input broadcasting signal, and compares a video index of an advertisement signal to be detected with the calculated video index of each frame of the broadcasting signal. In addition, the target video detecting apparatus detects a predetermined sequence of frames having video indexes that match a sequence of video indexes of the advertisement signal from the broadcasting signal. In addition, the target video detecting apparatus compares video indexes from a start frame of the detected plurality of frames and the corresponding frame of the advertisement signal in order to detect an advertisement signal from the broadcasting signal.