To prevent the occurrence of a ringing noise in a multilayer circuit board and to prevent the occurrence of a simultaneous switching noise of a circuit for a power source or a circuit for a ground.

The multilayer circuit board comprises a core board 5 having a through conductor 3 and a connecting land 4 extended from the conductor 3 in an insulating base 2, a multilayer wiring part having a plurality of insulating layers 7 and wiring conductor layers 8 laminated on the surface of the core board 5, and an insulating coating layer 12. An opening 13 having an area of the area or more of the land 4 is formed in a region of a wiring conductor layer 9 opposed to the land 4, and an opening 14 having the area of the area or less of the opening 13 and the area of the sectional area or more of the conductor 3 is formed in a region of the coating layer 12 opposed to the opening 13. Since the electromagnetic bond of the land 4 to the layer 9 is small, the mismatching of the characteristic impedance can be prevented. Since the inductance value of the layer 9 can be reduced, the ringing noise or the simultaneously switching noise can be reduced.