A plurality of images and image features of each of the plurality of images are stored in a form correlated with the images in an external storage device of an image retrieval apparatus. In retrieval of a desired image from the plurality of images that have been stored in the external storage device, a plurality of image features regarding one image are acquired by varying, over a predetermined range, each of the image features that have been stored in the external storage device. A fuzzy image search is conducted by calculating the degree of similarity between each of the plurality of images and a retrieval source image based upon the image features that have been acquired and the image features of the retrieval-source image.