Provided is an image search system capable of searching for an image that differs in a specific part from an original image. A reception unit receives designation of a partial region in an original image to be processed and a process content for the partial region. A search unit searches for an image identical or similar to a processed image, which is obtained by applying a process of the process content to the partial region of the original image, based on: a plurality of kinds of feature information on a region other than the partial region of the processed image or of the original image; and at least one piece of feature information selected based on the process content from among a plurality of kinds of feature information on the partial region of the processed image or of the original image.