A laser processing machine comprising: a beam irradiation unit (30, 35, 36) including a plurality of optical components and a processing head, and configured to convert a laser beam, which is divergent light, to collimated light and then to condense the light to irradiate a sheet metal; a photodetection element configured to detect intensity of reflected light reflected by an inspected optical component that is one of the plurality of optical components; and a control device, characterized in that the control device is configured to: execute control in such a manner that a pierced hole is formed by irradiating a laser beam emitted from the processing head of the beam irradiation unit (30, 35, 36), by piercing the sheet metal for cutting the sheet metal to manufacture a product, and then the pierced hole is irradiated with a laser beam emitted from the processing head of the beam irradiation unit (30, 35, 36) as inspection light, whereby a laser output of the inspection light is lower than a laser output of the laser beam for piercing the sheet metal; and compare, with a threshold, the intensity of the reflected light detected by the photodetection element during the irradiation with the inspection light, to detect whether the inspected optical component is deteriorated, or a degree of the deterioration. a beam irradiation unit (30, 35, 36) including a plurality of optical components and a processing head, and configured to convert a laser beam, which is divergent light, to collimated light and then to condense the light to irradiate a sheet metal; a photodetection element configured to detect intensity of reflected light reflected by an inspected optical component that is one of the plurality of optical components; and a control device, characterized in that the control device is configured to: execute control in such a manner that a pierced hole is formed by irradiating a laser beam emitted from the processing head of the beam irradiation unit (30, 35, 36), by piercing the sheet metal for cutting the sheet metal to manufacture a product, and then the pierced hole is irradiated with a laser beam emitted from the processing head of the beam irradiation unit (30, 35, 36) as inspection light, whereby a laser output of the inspection light is lower than a laser output of the laser beam for piercing the sheet metal; and compare, with a threshold, the intensity of the reflected light detected by the photodetection element during the irradiation with the inspection light, to detect whether the inspected optical component is deteriorated, or a degree of the deterioration. execute control in such a manner that a pierced hole is formed by irradiating a laser beam emitted from the processing head of the beam irradiation unit (30, 35, 36), by piercing the sheet metal for cutting the sheet metal to manufacture a product, and then the pierced hole is irradiated with a laser beam emitted from the processing head of the beam irradiation unit (30, 35, 36) as inspection light, whereby a laser output of the inspection light is lower than a laser output of the laser beam for piercing the sheet metal; and compare, with a threshold, the intensity of the reflected light detected by the photodetection element during the irradiation with the inspection light, to detect whether the inspected optical component is deteriorated, or a degree of the deterioration.