PURPOSE: To eliminate partial temperature difference on the joining surface, by causing the welding jig to contact flatly with the contact face of base metal, when welding in the captioned method by holding the laminated base metal and joining member between electrodes and supplying power.

CONSTITUTION: A laminated base metal 1 and a joining member 2 are held between upper and lower electrodes 3, 4 at specified pressure, and a specified current is passed between the two electrodes to weld the base metal 1 and member 2 by using the heat generated from the joining surface thereof. At this time, an approximately V-shaped contact surface 8 formed at the end of the base metal 1 and a contact surface 9 of an approximately V-shaped welding jig 5 contacting separably and tightly are brought to mutual surface contact at specified pressure. As a result, the heat on the joining surface is transmitted in the direction of long piece part of the base metal 1 and the direction of the jig 5. Therefore, occurrence of unwelded part due to partial temperature difference on the joining surface may be prevented.