A laser cutting device includes a control unit which sets a steady oxygen concentration, a moving speed of a laser nozzle and laser beam steady control conditions based on a material and a plate thickness of the workpiece, decreases the moving speed of the laser nozzle to a first setting speed when the laser nozzle arrives a first setting position in front of an end point of a cutting trajectory, and decreases a relative moving speed of the laser nozzle to a second setting speed by varying the oxygen concentration of the cutting gas and the control condition of the laser beam when the laser nozzle arrives at a second setting position.