A circuit board is provided that includes an outermost conductor layer including a plurality of terminals for flip-chip bonding and an outermost resin insulating layer defining a first opening and a second opening in an electronic-component mounting region. One of a power supply terminal and a ground terminal is exposed in the first opening. A plurality of signal terminals are exposed in the second opening. The resin insulating layer includes a reinforcing portion that defines an inner bottom surface of the second opening. A height of a portion of the terminal exposed in the first opening, the portion projecting from an inner bottom surface of the first opening, is greater than a height of portions of the terminals exposed in the second opening, the portions projecting from the inner bottom surface of the second opening.