An object of the present invention is to realize an image display apparatus which is capable of realizing a real-time display of an image based on a radio signal, and of coping with a case where a viewer such as a doctor overlooks an image. The image display apparatus includes a storage unit 11 which retains an electric signal and the like output from a switching unit 10 for a predetermined time and an image data generator 12 which generates predetermined image data based on the electric signal output from the switching unit 10 or the electric signal stored in the storage unit 11. Since the image display apparatus has a configuration that the image data generator 12 not only receives the electric signal directly from the switching unit 10, but also receives the electric signal to which a predetermined time lag is given in the storage unit 11, thereby enabling a display of a real-time image and a past image to which the predetermined time lag is given with respect to the real-time image.
