A circuit board includes a flexible wiring board with a reinforcing member. The flexible wiring board has a first, second and third sections. The reinforcing member is embedded in a cavity in the first section of the wiring board, and is sandwiched by a pair of resin layers provided below and above. A pair of wiring layers are disposed on the pair of the resin layers, respectively. The metal reinforcing member has either a plate shape or a frame shape. The first section of the wiring board is positioned closer to one of the wiring layers than to another of the wiring layers in a vertical direction.