PURPOSE: To make conductive bonding easy and sure, by making the thickness of a bump electrode in a section in the direction parallel to a semiconductor substrate smaller than the height dimension of the bump electrode in the direction vertical to the semiconductor substrate.

CONSTITUTION: The thickness of a bump electrode 20 in a section in the direction parallel to the surface of a semiconductor substrate 10 is made smaller than the height dimension of the bump electrode 20 in the direction vertical to the surface of a semiconductor substrate 10. As the substantial thickness of the bump electrode 20 becomes smaller than its height, the bump electrode 20 easily deforms and absorbs the irregularity of height, when the bump electrode 20 is pressed against conductor 31 of the wiring substrate 30 with a normal pressure. Thereby, the bump electrode 20 can be surely bonded with the conductor on the wiring substrate without applying a large pressure, even if the irregularity exists in the height dimension of the bump electrode.