An electromagnetic bandgap structure and a printed circuit board that solve a mixed signal problem are disclosed. In accordance with embodiments of the present invention, the electromagnetic bandgap structure includes a first metal layer; a first dielectric layer, stacked in the first metal layer; a second metal layer, stacked in the first dielectric layer, and having a holed formed at a position of the second dielectric layer; a second dielectric layer, stacked in the second metal layer; a metal plate, stacked in the second dielectric layer; a first via, penetrating the hole formed in the second metal layer and connecting the first metal layer and the metal plate; a third dielectric layer, stacked in the metal plate and the second dielectric layer; a third metal layer, stacked in the third dielectric layer; and a second via, connecting the second metal layer to the third metal layer.