To provide a spot welding apparatus for welding a workpiece, by which workability is improved by attaining light weight and stable welding quality is maintained.

This is a laser spot welding apparatus 10 having a laser head 15 that converges laser beam outputted from a laser oscillator to emit it to workpieces W1, W2. The apparatus includes: a first arm 12a with a laser head 15 installed in the tip end thereof; a second arm 12b with the tip end thereof arranged in a position oppositely facing the laser head 15; and a driving means for clamping/pressurizing the workpieces W1, W2 using the laser head 15 of the tip end of the first arm 12a and the tip end of the second arm 12b. Then, in a state where the workpieces W1, W2 are clamped/pressurized with a lid body 20 in the lower end of the laser head 15 and with the tip end of the second arm 12b by the driving means, the workpieces W1, W2 are irradiated with a laser beam by the laser head 15.