A spot welding electrode housing apparatus for housing electrodes for use in spot welding in such a manner that each of the electrodes is mountable on an end of a shank of a welding gun, the apparatus comprising: a rotor including a plurality of recesses (23, 24) opening in a same direction around a rotation axis and a hollow portion therein, each of the recesses (23, 24) receiving a corresponding one of the electrodes inserted therein from a distal end thereof and housing and holding the corresponding one of the electrodes such that a portion of the corresponding one of the electrodes mounted on the shank partially juts out of an opening of each of the recesses (23, 24); a biasing member housed in the hollow portion, and configured to rotationally bias the rotor toward one direction around the rotation axis; and a rotation regulator positioned adjacent to the rotor in a direction of the rotation axis, and configured to allow the rotor to abut against a side surface of a portion of one of the electrodes mounted on the shank and housed and held in a corresponding one of the recesses (23, 24) and thereby to regulate a rotation of the rotor toward the one direction around the rotation axis when the rotor is allowed to rotate toward the other direction around the rotation axis against a biasing force of the biasing member, characterized in that the rotation regulator has an anti-interference portion (71 a) having a step in the other direction around the rotation axis such that a surface of the anti-interference portion opposite to the rotor is closer to the rotor than a surface of a portion of the rotation regulator in the one direction around the rotation axis opposite to the rotor is, and the anti-interference portion is configured to avoid an interference with the end of the shank when one of the electrodes is mounted on the end of the shank. a rotor including a plurality of recesses (23, 24) opening in a same direction around a rotation axis and a hollow portion therein, each of the recesses (23, 24) receiving a corresponding one of the electrodes inserted therein from a distal end thereof and housing and holding the corresponding one of the electrodes such that a portion of the corresponding one of the electrodes mounted on the shank partially juts out of an opening of each of the recesses (23, 24); a biasing member housed in the hollow portion, and configured to rotationally bias the rotor toward one direction around the rotation axis; and a rotation regulator positioned adjacent to the rotor in a direction of the rotation axis, and configured to allow the rotor to abut against a side surface of a portion of one of the electrodes mounted on the shank and housed and held in a corresponding one of the recesses (23, 24) and thereby to regulate a rotation of the rotor toward the one direction around the rotation axis when the rotor is allowed to rotate toward the other direction around the rotation axis against a biasing force of the biasing member, characterized in that the rotation regulator has an anti-interference portion (71 a) having a step in the other direction around the rotation axis such that a surface of the anti-interference portion opposite to the rotor is closer to the rotor than a surface of a portion of the rotation regulator in the one direction around the rotation axis opposite to the rotor is, and the anti-interference portion is configured to avoid an interference with the end of the shank when one of the electrodes is mounted on the end of the shank.