An image display apparatus includes a storage portion to store application data and reduced image data thereof, in association with each other, a position detection portion to detect a position designated by the user on a display surface of a display portion, an enlargement operation detection portion to detect an enlargement operation, a first image display portion to display a first display image generated from the reduced image data as a preview image, a process target determination portion to determine process target data from the reduced image data and the application data, based on a magnification set based on the amount of operation in the enlargement operation, a second display image generation portion to generate a second display image based on the process target data, in response to the enlargement operation being detected, and a second image display portion to display the second display image as a preview image.