An electromagnetic contactor has a base plate having an aperture hole; an arc extinguishing chamber including a fixed terminal having a vent portion and a pipe obliquely inserted from outside a wall surface and connecting the vent portion; and a bottomed tubular cap in which one end thereof is open. An arc extinguishing chamber connection portion is formed by the arc extinguishing chamber and a first connection member having a tube portion connected to the arc extinguishing chamber and a flange portion contacting with the base plate. A cap connection portion is formed by the cap and a second connection member having a tube portion connected to the cap and a flange portion connected to the base plate. The arc extinguishing chamber connection portion and the cap connection portion are in communication through the aperture hole of the base plate.