1. An image processing apparatus comprising: instructed-position detecting means for receiving an instruction operation by a user on a display screen of a display device, detecting a position where the instruction operation is performed, and outputting the detected position; storing means for storing a plurality of image data items each including information corresponding to a search key; search-key display controlling means for causing at least one search key to be selectively displayed on the display screen of the display device; searching means for, if the search key displayed on the display screen of the display device is instructed by the search-key display controlling means through the instructed-position detecting means, searching the storing means for the image data corresponding to the instructed search key to extract the image data; and display controlling means for collectively displaying images corresponding to the image data extracted by the searching means in a certain part on the display screen.