A similar image search system is provided and searches for images similar to a search key image, where a number of searched images of person are classified into a number of groups based on a similarity between the respective images. A grouping display is performed in which at least one of the images that belongs to each group is displayed in a display region that is provided for each group. The grouping display is performed in such a manner that the order of the similarity between each group and the search key image can be visually recognized.