PURPOSE: To build-in various kinds of circuit elements in an inner layer of a multilayer wiring board and to enable high concentration of an electronic circuit by bonding and laminating a plurality of electronic circuit boards in multilayer construction through an insulating resin layer with a circuit element side of at least one board inward.

CONSTITUTION: A plurality of printed wiring boards whereon a desired circuit conductor layer 9 is formed at a layer of a front or both sides of an insulating substrate 8 are prepared. A recessed section is partially provided and fixed to make a semiconductor integrated circuit element 10 as thin as possible for easy mount. Its aluminum electrode thermal and the circuit conductor layer 9 whereto gold plating is applied are connected by a metal wire 11 of a gold line, etc., and further coated with a mold resin layer 12 to constitute an electronic circuit board having a specified function. A plurality of these electronic circuit boards are laminated, and an insulating resin 13 is bonded thereto and laminated in multilayer construction to manufacture a multilayer electronic circuit board wherein the semiconductor integrated circuit element 10 is built-in. Thereby, it is possible to realize high concentration of structure wherein a circuit element with constitutes an electronic circuit is built-in between layers of a multilayer printed wiring board and arranged in multilayer construction.