An image search device includes a common memory and a plurality of parallel processors for executing a same instruction. The image search device transfers, from storage, a plurality of representative feature vectors, which respectively represent a plurality of clusters including a plurality of image feature vectors, stores, in the common memory, one or more query feature vectors extracted from an image serving as a query, calculates a distance between the plurality of transferred representative feature vectors and the query feature vector using the plurality of parallel processors, and selects one or more of a plurality of images based on a distance between the plurality of image feature vectors, which belong to the cluster selected by the calculated distance, and the query feature vector.