The present invention discloses an apparatus for automatically detecting television advertisements comprising: a video frame buffer for storing a first group of video frames and a second group of video frames received by a television in which a scene change rate of the second group of video frames is substantially different from that of the first group of video frames; a video scene change detection and calculation unit for reading the first and second groups of video frames stored in the video frame buffer, determining the last frame immediately before the first group of video frames changes into the second group of video frames as a prompting frame, and calculating a correlation between a newly received video frame and the prompting frame; a prompting signal generation unit for generating a prompting signal when the correlation between the newly received video frame and the prompting frame, which is detected by the video scene change detection and calculation unit, is equal to or larger than a predetermined threshold; and a control unit for controlling the operation of the video scene change detection and calculation unit. The present invention also discloses a method for automatically detecting television advertisements.