An electrode unit joining structure for a superconducting wire includes: a superconducting wire comprising a first base member, a first superconducting layer provided on the first base member, and a first electroconductive layer provided on the first superconducting layer; an electrode provided on the first electroconductive layer at an end portion of the superconducting wire; and a superconducting cover tape comprising a second base member, a second superconducting layer provided on the second base member, and a second electroconductive layer provided on the second superconducting layer, the superconducting cover tape being provided so as to cover at least part of the electrode, wherein the second electroconductive layer of the superconducting cover tape is disposed on the electrode side, and the electrode, the superconducting wire, and the superconducting cover tape are electrically connected to each other.