According to the present invention, face parts to be compared are set by the comparison target setting section based on the number of images of a group of search target images. Then, a retrieval target image and each image of the group of search target images is compared by the set face parts. An image with a particular correlation is determined to be a similar image and retrieved from the group of images to be compared. Thereby, it is possible to perform quick retrieval based on the number of images of the group of search target images.