A method of manufacturing a rotary electric machine armature that includes a cylindrical armature core in which a plurality of slots that extend in an axial direction are disposed in a circumferential direction and a coil wound around the armature core, the slots having respective radially opening portions that open in a radial direction, and the coil being constituted by joining a plurality of segment conductors to each other, the method comprising: a preparation step of preparing a plurality of the segment conductors and preparing the armature core, the segment conductors having respective conductor side portions that extend along the axial direction and respective crossover portions connected to the conductor side portions on an outer side of the armature core in the axial direction, the conductor side portions being provided with respective joint portions that have respective facing surfaces; an arrangement step of arranging, when the segment conductor, among the plurality of segment conductors, the crossover portion of which is disposed on one side in the axial direction with respect to the armature core, is defined as a first segment conductor and another segment conductor, the crossover portion of which is disposed on the other side in the axial direction with respect to the armature core, is defined as a second segment conductor, at least either the conductor side portions of the first segment conductor or the conductor side portions of the second segment conductor in the slots such that the facing surface of one of the joint portions of the first segment conductor and the facing surface of one of the joint portions of the second segment conductor face each other; a regulation step of regulating movement of the conductor side portions in the radial direction; and a joint step of joining the joint portions of the first segment conductor and the joint portions of the second segment conductor to each other while maintaining a regulating state in the regulation step; characterized by a joint material arrangement step of disposing a conductive joint material on at least one of the facing surfaces which face each other, the conductive joint material joining the joint portions of the first segment conductor and the joint portions of the second segment conductor to each other while securing conductivity, wherein the joint step includes joining the joint portions of the first segment conductor and the joint portions of the second segment conductor to each other by heating the conductive joint material. a preparation step of preparing a plurality of the segment conductors and preparing the armature core, the segment conductors having respective conductor side portions that extend along the axial direction and respective crossover portions connected to the conductor side portions on an outer side of the armature core in the axial direction, the conductor side portions being provided with respective joint portions that have respective facing surfaces; an arrangement step of arranging, when the segment conductor, among the plurality of segment conductors, the crossover portion of which is disposed on one side in the axial direction with respect to the armature core, is defined as a first segment conductor and another segment conductor, the crossover portion of which is disposed on the other side in the axial direction with respect to the armature core, is defined as a second segment conductor, at least either the conductor side portions of the first segment conductor or the conductor side portions of the second segment conductor in the slots such that the facing surface of one of the joint portions of the first segment conductor and the facing surface of one of the joint portions of the second segment conductor face each other; a regulation step of regulating movement of the conductor side portions in the radial direction; and a joint step of joining the joint portions of the first segment conductor and the joint portions of the second segment conductor to each other while maintaining a regulating state in the regulation step; characterized by a joint material arrangement step of disposing a conductive joint material on at least one of the facing surfaces which face each other, the conductive joint material joining the joint portions of the first segment conductor and the joint portions of the second segment conductor to each other while securing conductivity, wherein the joint step includes joining the joint portions of the first segment conductor and the joint portions of the second segment conductor to each other by heating the conductive joint material.