Provided is a spot welding electrode housing apparatus having a reduced size such that an operation of mounting electrodes on a welding gun is less likely to affect a line takt time. Specifically, a rotation regulator positioned adjacent to a rotating plate in a direction of a rotation axis is configured to allow the rotating plate to abut against an electrode housed and held in a first recess or a second recess and thereby to regulate a rotation of the rotating plate toward one direction around the rotation axis when the rotating plate rotationally biased by a spiral spring toward the one direction around the rotation axis is allowed to rotate toward the other direction around the rotation axis against a biasing force of the spiral spring.