A laser processing device includes a laser oscillator, an optical fiber that is a multi-clad fiber, a beam control mechanism provided in the laser oscillator, and a laser light emitting head attached to the optical fiber. The beam control mechanism includes a condenser lens, an optical path changing and holding mechanism that is disposed between the condenser lens and an incident end face of the optical fiber and changes an optical path of laser light LB, and a controller that controls an operation of the optical path changing and holding mechanism. The beam control mechanism controls a power distribution of the laser light by changing an incident position of the laser light on the incident end face.