A chip is bonded on a circuit board by aligning in position bumps with board electrodes with interposition of an anisotropic conductive layer between the chip and the circuit board. The anisotropic conductive layer is a mixture of an insulating resin, conductive particles and an inorganic filler. The chip is pressed against the board with a pressure force of not smaller than 20 gf per bump by virtue of a tool, while warp of the chip and the board is connected, the bumps are compressed, and the insulating resin is hardened.