Laser processing device capable of reducing intensity of reflected laser beam

A laser processing device for carrying out laser processing of an object to be processed by irradiating a laser beam onto the object, the laser processing device comprising:

• a laser processing commanding part configured to output a laser processing command including at least one of laser piercing, laser cutting, laser marking and laser welding;
• a detector configured to monitor an intensity of a reflected laser beam from the object;
• a memory configured to store the intensity of the reflected laser beam monitored by the detector, and a laser output condition including a laser power command value, a pulse irradiation time and a pulse interval;
• a pre-processing commanding part configured to, prior to the laser processing command, command a pre-processing including another laser output condition different from the laser processing command;
• a comparing part configured to compare the intensity of the reflected laser beam stored in the memory to a first judgment value and/or a second judgment value lower than the first judgment value;
• an output condition changing part configured to change the laser output command of the pre-processing command, based on a comparison result by the comparing part;
• and
• a pre-processing terminating part configured to terminate the pre-processing by the pre-processing command, based on a predetermined condition.