A multi-layered board includes: a middle conductive layer; a first dielectric layer that is disposed directly on a first surface of the middle conductive layer; a second dielectric layer that is disposed directly on a second surface of the middle conductive layer; a first outer surface conductive layer that is disposed directly on an outer side of the first dielectric layer; and a second outer surface conductive layer that is disposed directly on an outer side of the second dielectric layer. The first outer surface conductive layer serves as a first outer surface of the multi-layered board, and the second outer surface conductive layer serves as a second outer surface of the multi-layered board. The middle conductive layer is solidly formed over an entire planar direction of the multi-layered board. The first dielectric layer and the second dielectric layer each independently have a thickness variation of 15% or less.