To provide a working apparatus with which the higher precise working can be obtained by making finer the diameter of liquid jetted from a nozzle than that of the liquid from the conventional nozzle.

The working apparatus 1 is provided with a high pressure pump 5 for supplying water W, a laser beam oscillator 4 for oscillating the laser beam L and the nozzle 14 machined into a conical surface 14A shrinking the diameter to the tip part in the inner part. In the inner surface of this nozzle, a transparent conical member 15 is arranged, and on the outer peripheral conical surface 15A of this conical member, a coating layer 15C for reflecting the laser beam is formed and also, at this center, a liquid flowing passage 15B for making flow of the liquid from the high pressure pump is bored. The liquid from a liquid supplying means is made to flow in the above liquid flowing passage, and this liquid is jetted to the working material and also, the laser beam from the laser beam oscillator is made incident from the rear end part of the conical member and reflected and converged to the coating layer to irradiate the working material with the laser beam guided with the jetted liquid.