In a semiconductor device bonded to a motherboard with a bonding material having a melting point of 200° C. to 230° C., a bonding material 15 which is a die bonding material for bonding a semiconductor element 13 to a semiconductor substrate 11 is a Bi alloy containing 0.8 wt % to 10 wt % of Cu and 0.02 wt % to 0.2 wt % of Ge, so that the bonding material 15 for bonding the semiconductor element 13 to the semiconductor substrate 11 is not melted when the semiconductor device is bonded to the motherboard by reflowing. It is therefore possible to suppress poor connection on the semiconductor element 13, thereby securing the mountability and electrical reliability of the semiconductor device.