To facilitate the operation and to extend the life of a working electrode by unifying the control system of a seam welding machine controller.

In the control moving and positioning the electrode for the seam welding machine with respect to works W1, W2, the usage frequency of working electrode jigs 1, 2 designated to a specified work in accordance with a working program and working condition or the like is calculated every time welding is finished, the calculated usage frequency is compared with a pre-set allowable usage frequency, the welding work used electrode jigs 1, 2 is suspended to start on the condition that the usage frequency of the electrode jig coincides with the set usage frequency.