Abstract: An apparatus for exchanging electrode chips used for resistance welding. The apparatus includes a base to which a shaft is rotatably mounted. A power source is connected to one end of the shaft to rotate the shaft. An electrode chip-withdrawing knife tool is made of a board connected to the other end of the shaft. The knife tool is provided with recesses which are radially directed about the axis of the shaft. The recesses have their respective knife edge portions each of which is fitted into an annular groove formed between the step portion at the front end of the shank of each arm of a welding gun and the electrode chip fitted over the shank. An electrode chip supply holder in which new polished electrode chips are received is held by a guide member.