A coupling structure in a wiring board including a printed wiring board and a flexible printed wiring board overlaid on the printed wiring board. The printed wiring board includes a first conductive line on a surface adjacent to the flexible printed wiring board. The flexible printed wiring board includes a second conductive line on a surface on an opposite side from the printed wiring board. The flexible printed wiring board includes a conduction-purpose through hole adjacent to the second conductive line and in which a section of the first conductive line is disposed. The first conductive line of the printed wiring board and the second conductive line of the flexible wiring board are electrically connected to each other with a conductive member disposed in the conduction-purpose through hole. The conductive member is covered with a resin having an insulating property.