A composite wiring board includes a first wiring board having an opening for housing an electronic component, and including a plurality of first connection pads on an upper surface and a plurality of second connection pads on a lower surface, and a second wiring board having the electronic component mounted on a lower surface, including a third connection pad provided on the lower surface on an outer peripheral side and bonded to the first connection pad through a solder, and disposed on the first wiring board so as to cover the opening, in which a grounding inner wall conductor layer is deposited on an inner wall of the opening around the electronic component, and a grounding conductor layer is deposited on the lower surface of the second wiring board and connected to the inner wall conductor layer through a solder.