In a circuit board-connecting portion 10, a first connecting portion 15 and a second connecting portion 20 are disposed in facing relation such that first conductors 14 contact second conductors 19, and also a first substrate 12 and a second substrate 17 are fixed to each other by an adhesive 22. The first connecting portion 15 has rigid members 24 provided at a reverse surface 12B of the first substrate 12 which is a soft substrate, and the rigid members 24 are disposed along a direction of a thickness of the first substrate 14, and are provided at positions corresponding to at least parts 14A of the first conductors 14.