An EBG (Electromagnetic Band Gap) structure according to an embodiment includes: an electrode that is made of a first conductor; a first insulating layer that is provided on the electrode; a patch unit that is provided in substantially parallel with the electrode on the first insulating layer, the patch unit including a first gap, the patch unit being made of a second conductor; a second insulating layer that is provided on the patch unit; a first via that is provided between the patch unit in the first insulating layer and the electrode and connected to the patch unit and the electrode; and a second via that is provided in the first and second insulating layers, the second via piercing the first gap and being connected to the electrode.