To provide a wiring board which meets a requirement of improving electrical reliability.

A wiring board 4 according to an embodiment of the invention includes a first insulating layer 7a containing a first resin material 10a, a plurality of first inorganic insulating particles 11a, and a first through hole P1, as well as a first penetrating conductor 8a formed inside the first through hole P1. The first insulating layer 7a includes a first resin insulating part 7a1 consisting of the first inorganic insulating particles 11a distributed in the first resin material 10a and a first inorganic insulating part 7a2 which is made up of the same material as the inorganic insulating particles 11a and exists between the first resin insulating part 7a1 and the first penetrating conductor 8a.