A main object of the present invention is to provide fine particles, a particle group, an anti-counterfeiting ink, an anti-counterfeiting toner, an anti-counterfeiting sheet, and an anti-counterfeiting medium enabling to achieve a high level of authentication. The object of the present invention is achieved by providing the fine particle comprising an identification information group including multiple types of identification information identifiable by magnification, characterized in that the identification information group includes first identification information and second identification information which cannot be identified at any magnifying power capable of identifying the first identification information.