A coupled via structure includes a plate via penetrating through an board body and having first and second plates spaced apart from each other by a first gap distance, a contact pad connected to the plate via on a surface of the board body and having first and second contacts connected to the first and second plates, respectively, and a connection line connected to the contact pad on the surface of the board body and having first and second lines connected to the first and second contacts, respectively, and spaced apart from the first line by a second gap distance. Accordingly, the deviation of the characteristic impedance is reduced (or, alternatively, minimized) between the coupled via structure and the coupled signal line.