The present invention provides an AF-area display apparatus integrated in a lens unit that is interchangeably mounted on a camera and has an automatic focusing device for controlling focusing in such a way that the camera is focused on a photographic subject within an AF area in an imaging area of the camera, or connected as an auxiliary device to the lens unit, the AF-area display apparatus comprising: an AF-area obtaining device that obtains the AF area currently set in the automatic focusing device; a video signal generating device that generates a video signal for displaying the AF area obtained through the AF-area obtaining device; and a video signal outputting device that outputs the video signal generated by the video signal generating device.