The laser processing device includes a laser head that emits laser light and a camera that acquires a surface image of a processing member after being irradiated with the laser light. The laser processing device further includes an image processor that performs image processing on an acquired surface image and calculates a diameter of a processing mark, and an autofocus controller that derives an optimum focal position of the laser light based on the diameter of the processing mark. In addition, the laser processing device includes a driver that moves the laser head in an emission direction of the laser light to allow the laser light to be condensed at an optimum focal position based on the derivation result of the autofocus controller.