Abstract: A bearing is located at the front of a frame and through means of this bearing an electrode disposed upon one side of a welding gap and an electrode disposed upon the other side of the welding gap can be positioned opposite each other upon a horizontal central axis line, so that with the electrode part upon one side of the welding gap having an electrode bit at the front thereof being movable forwardly and backwardly while connected with the bearing, an object to be welded can be gripped between the electrode bit on the one side and the electrode bit on the other side; and if the electrode on the other side which is provided with a bracket having the other electrode bit disposed at its tip, and which is attached externally to the bearing, is rotated around the electrode upon the one side, spot welding in many different positions, including upwardly, downwardly and sideways, can be easily achieved.