PURPOSE: To provide a circuit board on which high-density mounting can be performed and soldering can be performed in a stable state by using a reflow furnace.

CONSTITUTION: The title circuit board is composed of a multilayered substrate formed by joining a plurality of substrates to each other and constituted to high-density mounting in such a way that blind through holes 14 are formed through substrates 11 and 13 on the external surface at the parts of connection lands 25 so as to connect the lands 25 to a wiring pattern 26 on the other surface. At the same time, excellent soldering can be performed on the circuit board with a reflow furnace by respectively forming the holes 14 or dummy blind through holes 27 at the connection lands 25 connected to electrodes 24 at both ends of parts.