A laser processing device, comprising at least: a laser oscillator that generates laser light; a fiber bundle that is formed by bundling a plurality of optical fibers so as to have a predetermined arrangement relationship; a beam control mechanism that is provided in the laser oscillator; and a plurality of laser light emitting heads that are attached to emission ends of the plurality of optical fibers, respectively, and illuminate the laser light to workpieces, respectively, wherein the beam control mechanism includes at least a condenser lens that receives the laser light, and condenses the laser light at a predetermined magnification, characterized in that a plurality of optical path changing mechanisms that are provided on an optical path of the laser light traveling between the condenser lens and an incident end face of the fiber bundle, and change the optical path of the laser light, and a controller that controls operations of the plurality of optical path changing mechanisms, and the beam control mechanism causes the laser light to be incident on one optical fiber selected from among the plurality of optical fibers, and causes the laser light to be emitted from the laser light emitting head attached to the one optical fiber, wherein each of the plurality of optical path changing mechanisms corresponds to each of the plurality of optical fibers, each of the plurality of optical path changing mechanisms includes a parallel plate-shaped optical member (51, 52, 53) that transmits the laser light, and is provided to be tiltable about a tilt axis intersecting with an optical axis of the laser light, and an actuator that is coupled to the optical member (51, 52, 53), the controller moves the optical member (51, 52, 53) included in one optical path changing mechanism among the plurality of optical path changing mechanisms to a predetermined position, and drives the actuator included in the one optical path changing mechanism, and causes the laser light to be incident on the optical fiber corresponding to the one optical path changing mechanism by tilting the optical member (51, 52, 53) coupled to the actuator about the tilt axis, wherein a plurality of the optical members (51, 52, 53) is configured to be movable between an outside of the optical path and the predetermined position on the optical path of the laser light traveling between the condenser lens and the incident end face of the fiber bundle. a laser oscillator that generates laser light; a fiber bundle that is formed by bundling a plurality of optical fibers so as to have a predetermined arrangement relationship; a beam control mechanism that is provided in the laser oscillator; and a plurality of laser light emitting heads that are attached to emission ends of the plurality of optical fibers, respectively, and illuminate the laser light to workpieces, respectively, wherein the beam control mechanism includes at least a condenser lens that receives the laser light, and condenses the laser light at a predetermined magnification, characterized in that a plurality of optical path changing mechanisms that are provided on an optical path of the laser light traveling between the condenser lens and an incident end face of the fiber bundle, and change the optical path of the laser light, and a controller that controls operations of the plurality of optical path changing mechanisms, and a plurality of optical path changing mechanisms that are provided on an optical path of the laser light traveling between the condenser lens and an incident end face of the fiber bundle, and change the optical path of the laser light, and a controller that controls operations of the plurality of optical path changing mechanisms, and the beam control mechanism causes the laser light to be incident on one optical fiber selected from among the plurality of optical fibers, and causes the laser light to be emitted from the laser light emitting head attached to the one optical fiber, wherein each of the plurality of optical path changing mechanisms corresponds to each of the plurality of optical fibers, each of the plurality of optical path changing mechanisms includes a parallel plate-shaped optical member (51, 52, 53) that transmits the laser light, and is provided to be tiltable about a tilt axis intersecting with an optical axis of the laser light, and an actuator that is coupled to the optical member (51, 52, 53), the controller moves the optical member (51, 52, 53) included in one optical path changing mechanism among the plurality of optical path changing mechanisms to a predetermined position, and drives the actuator included in the one optical path changing mechanism, and causes the laser light to be incident on the optical fiber corresponding to the one optical path changing mechanism by tilting the optical member (51, 52, 53) coupled to the actuator about the tilt axis, wherein a plurality of the optical members (51, 52, 53) is configured to be movable between an outside of the optical path and the predetermined position on the optical path of the laser light traveling between the condenser lens and the incident end face of the fiber bundle.