An image retrieval device and method capable of high speed image retrieval. The image retrieval device has a first coefficient transforming section to transform a first group of image feature descriptors extracted from image data accumulated in an image database and to generate a second group of image feature descriptors to be used for calculating similarity. The image retrieval device has a second coefficient transforming section to transform the first group of image feature descriptors extracted from image data of an inquired image and to generate a second group of image feature descriptors to be used for calculating similarity. The image retrieval device has a similarity calculating section to compare the second group of image feature descriptors for each piece of image data produced by the first coefficient transforming section with the second group of image feature descriptors for the inquired image transformed by the second coefficient transforming section.