To provide a highly reliable wiring board together with its manufacturing method where the filling characteristic of a resin plug body formed in an inner through hole conductor of a composite coaxial through hole conductor is high.

A wiring board 1 is provided with a composite coaxial through hole conductor which comprises an outer through hole conductor 8 and an inner through hole conductor 18. The inner through hole conductor 18 follows the shape of an inner peripheral surface 17C of an inner through hole 17 where it is formed, and comprises a cylindrical first conductor 18S, an upper sloped second conductor 18T1 whose inner diameter is tapered, and a lower sloped second conductor 18T2 whose inner diameter is tapered.