To solve the problem that it is not easy to control the impedance in a high frequency circuit board including striplines after forming the striplines, and this requires a matching circuit.

The circuit board comprises spacer conductors 30, 32 disposed between a strip conductor 6 and a ground conductor 10 laid on an inner layer of a multilayer board, and vias 20, 24 for electrically connecting the inner layer to the circuit board surface. The vias 24, 20 are connected to the spacer conductors 30, 32 and the ground conductor 10, respectively. The spacer conductors 30, 32 short-circuit the ends of the vias 20, 24 disposed on the circuit board surface, thereby grounding the conductors 30, 32. This substantially reduces the distance between the strip conductor 6 and the ground conductor 10, resulting in reduction of the impedance.