A circuit board includes a laminated body including insulation layers made of a flexible material that are stacked on one another. External electrodes are provided on a bottom surface of the laminated body. Ground conductors are provided in the laminated body and that are harder than the insulation layers. The laminated body includes a flexible region and a rigid region that is adjacent to the flexible region when viewed in plan from a z-axis direction. The rigid region is defined by the ground conductors when viewed in plan from the z-axis direction. The external electrodes are provided within the flexible region when viewed in plan from the z-axis direction.