Provided are a circuit board with enhanced moisture resist and the method of manufacturing the circuit board, and a circuit device and a method of manufacturing the circuit device. A circuit board of the present invention includes: a substrate; wirings formed on the main surface of the substrate; a cover layer covering the wirings excluding the regions to be connectors; back electrodes formed on the bottom surface of the substrate; and through-hole electrodes formed so as to penetrate the substrate, and thereby connecting the wirings and the back electrodes. On surfaces of each of the wirings in this circuit board, convex portions on the periphery of the substrate are set larger in width than convex portions in a center portion of the substrate. With this configuration, adhesion reliability between the wirings and the cover layer under a thermal cycle load can be enhanced.