A processing machine includes mirrors and to reflect a beam L oscillated from a laser oscillator to a predetermined surface on which a workpiece is arranged, optical axis operating mechanisms and to position an optical axis of the beam L at a desired target irradiation position by changing directions of the mirrors and, a camera sensor to capture an image of the target irradiation position and its periphery reflected in the mirror, and an error calibration mechanism to detect an error between the target irradiation position instructed to the optical axis operating mechanisms and an actual position of the optical axis of the beam L in the predetermined surface by referring to the image captured by the camera sensor. A correction amount to the optical axis operating mechanisms and is determined based on the error to irradiate the target irradiation position with the beam L during processing.