An electromagnetic contactor manufacturing method includes a step of forming an arc extinguishing chamber connection portion by simultaneously brazing a fixed terminal and a pipe penetrating and fixed to a tub-shaped arc extinguishing chamber, and a tube portion of a first connection member in communication with an open end portion of the arc extinguishing chamber; a step of forming a cap connection portion having a flange portion extending outward in a radial direction from an open end of a bottomed tubular cap; and a step of disposing a flange portion of the first connection member and a flange portion of a second connection member in close contact with a base plate in which an aperture hole is formed, and welding each of the flange portions to the base plate so that the arc extinguishing chamber connection portion and the cap connection portion are in communication through the aperture hole.