A plurality of protruding electrodes of a semiconductor chip are in contact with a plurality of electrodes formed on a semiconductor substrate, via a plurality of solder sections. In this state, the solder sections are melted so as to form a plurality of solder bonding sections joined to the protruding electrodes of the semiconductor chip and the electrodes of the semiconductor substrate. Moreover, a distance between a part of the semiconductor chip and the semiconductor substrate is larger than a distance between the other part of the semiconductor chip and the semiconductor substrate, extending at least some of the solder bonding sections. Thus, the solder bonding sections vary in height. Holes are then formed at least in a solder bonding section having a maximum height out of the solder bonding sections. After that, the solder bonding sections are solidified.