1. An image display apparatus having a first display region in which a plurality of main image data are displayed one at a time and a second display region in which sub image data is displayed within the first display region, the image display apparatus comprising: a face region detecting section configured to detect a face region in the main image data; a face importance degree determining section configured to determine a region importance degree of a detected face region; and a display position setting section configured to set a position of the second display region based on the region importance degree of the main image data displayed in the first display region.