Disclosed herein is a circuit substrate that includes a coil component mounted on the substrate having first and second land patterns and first and second dummy land patterns. The coil component includes a first signal terminal and a first dummy terminal which are provided on the first flange part, a second signal terminal and a second dummy terminal which are provided on the second flange part, and a wire wound around the winding core part and whose one end and other end are connected respectively to the first signal terminal and the second signal terminal. The coil component is mounted on the substrate such that the first and second signal terminals are connected respectively to the first and second land patterns and that the first and second dummy patterns are connected respectively to the first and second dummy land patterns.