The present invention addresses the problem of reducing a delay time difference between signals transmitted by means of a differential signal wires in a wiring board having glass cloth. A wiring boardcomprises: an insulating layer which includes fibers having a planar shape with translational symmetry with respect to two linearly independent, predetermined translational vectors, and a layer-likeinsulating material encapsulating the fibers; and through-holes formed at the starting and end points of a vector which is the sum of substantially integer multiples of the two translational vectors and which has the starting point on the planar shape.