To provide spot welding equipment in which switching into a desired fixed electrode can automatically be performed with a simple constitution, labor saving can be attained, and a sufficient strength can easily be imparted to a gun arm.

The spot welding equipment has a gun body 5 having a pressure electrode 13 and provided on the tip part of a robot arm 2 movable in a three-dimensional direction and having a rotatable wrist axis 4; a gun arm 6 provided fixedly to the gun body 5; and a fixed electrode holding member 21 holding a plurality of different fixed electrodes 22 and 23, and provided so as to be rotated relatively to the gun arm 6 in such a manner that each fixed electrode can selectively be aligned in the position confronted with the pressure electrode 13. The fixed electrode holding member 21 is engaged with a fixture 42 by the robot arm 2, and the gun arm 6 and the fixed electrode holding member 21 are relatively rotated. Thus, the desired fixed electrode held by the fixed electrode holding member 21 is aligned in a position confronted with the pressure electrode 13.