In order to inhibit the connection failure due to the degradation of the connection interface strength of the electrode pad and the warp thereof in the semiconductor device having an electrode pad, a metal layer formed on the electrode pad, and a metal bump formed on the metal layer, in the present invention, gold (Au) is contained in the metal layer, the metal bump is made of solder mainly made of Sn and designed to have an average height H of 100 .mu.m or less per unit area in the electrode pad, and the concentration of Au of the metal layer dissolved in the solder is set to 1.3.times.10.sup.-3 (Vol %) or less. More preferably, the metal bump contains palladium (Pd), and the solder coating for forming the metal bump on the electrode pad is performed by using the dipping and the paste printing in combination.