In a multilayer circuit board of the present invention, a plurality of
circuit substrates configured by forming a circuit pattern on an
insulating base material are stacked via an insulating layer, a
through-hole and a via hole are formed in the layering direction, and
laser processability and laser processing speed for a processing laser
beam used in formation of the through-hole and the via hole are about the
same for the insulating substrate material and the insulating layer.