Disclosed herein is an electromagnetic bandgap (EBG) pattern structure, including: a nonconductive substrate; and a pattern assembly formed on the substrate and including regularly arranged closed-loop patterns and open-loop patterns both of which are made of a conductive material. The EBG pattern structure is advantageous in that it can be used to manufacture new security products by applying its frequency characteristics to securities or IDs and in that it can be variously used in security technologies for preventing forgery and alteration because various security codes can be created by adjusting the variables of its EBG pattern.