A laser machining apparatus comprises a nozzle for ejecting a jet liquid to a workpiece and a liquid supply unit for supplying the jet liquid to the nozzle, while a laser beam is introduced into a jet liquid column ejected from the nozzle. The laser machining apparatus further comprises a laminar flow forming channel for supplying the jet liquid to the nozzle in a laminar state. The laminar flow forming channel includes a distribution channel formed by a cavity for annually distributing the jet liquid, which is supplied from the liquid supply unit, around an axis of the nozzle, an interconnecting channel disposed to be communicated with the distribution channel at the downstream side thereof in an axial direction of the nozzle and formed by an annular cavity around the axis of the nozzle to provide a narrower flow passage than the distribution channel, and a liquid reservoir chamber adjacently disposed upstream of the nozzle in the axial direction thereof and storing the jet liquid to be supplied to the nozzle. The liquid reservoir chamber has an outer peripheral edge being communicated with the interconnecting channel over an entire circumference of the annular shape thereof.