An electromagnetic bandgap structure and a printed circuit board that can solve a mixed signal problem between an analog circuit and a digital circuit are disclosed. In accordance with an embodiment of the present invention, an electromagnetic bandgap structure is stacked with a first metal layer, a first dielectric layer, a metal plate, a second dielectric layer and a second metal layer, and an odd number of vias can be serially connected through a metal line between the first metal layer and the metal plate. This electromagnetic bandgap structure can have a small size and a low bandgap frequency.