To provide a laser beam welding equipment that makes welding possible for a wide range by emitting a laser beam at planar right angle to a base material, in the form known as vertical incidence, while welding is performed by scanning the laser beam as a precondition.

A laser beam 5 passed through and converged by a condensing lens 3 is turned back by reflecting with a return mirror 4 and an optical path selecting mirror 6, and then further reflected with an irradiation mirror 7, so that the laser beam is emitted to the base material W in the form of vertical incidence. By synchronously moving the condensing lens 3 in the a-direction and the irradiation mirror 7 in the b-direction respectively, welding is performed on a welding length L. The welding length L is equalized with the moving amount M of the condensing lens 3 and with the moving amount N of the irradiation mirror 7.