PURPOSE: To enable wireless bonding with high density easily even when a normal Al electrode is used as a terminal electrode in the semiconductor element substrate of an IC, an LSI, etc., by forming a conductor projection on the wiring electrode side of a circuit board and connecting the circuit board and a semiconductor element.

CONSTITUTION: A circuit board 12, on which a plurality of wiring electrodes 11 are formed, is fixed to a support table heated at 150°C, tip spherical Au wires having 30μm are thermocompression-bonded successively onto the wiring electrodes 11, and columnar thermocompression-bonded Au projections 13 are formed. Thermocompression bonding is executed by applying ultrasonic vibrations to the tip spherical Au wires in the direction parallel with the surface of the circuit board and applying pressure to the tip spherical Au wires in the vertical direction, and the columnar thermocompression-bonded Au projections 3 can easily and continuously be formed. Semiconductor element substrates 15, on which Al terminal electrodes 14 are shaped, are placed onto the circuit board 12, in which the columnar thermocompression-bonded Au projections 13 are formed onto the wiring electrodes 11, and connecting sections, on which the columnar thermocompression-bonded Au projections 13 and the Al terminal electrodes 14 are put oppositely, are bonded through thermocompression bonding.