PROBLEM TO BE SOLVED: To provide a laser therapy apparatus favorably performing a treatment by suppressing speckle noise of laser beams with high beam quality.SOLUTION: The laser therapy apparatus includes: a laser source for emitting treatment laser beams multi-mode fibers for guiding the laser beams emitted from the laser source and an irradiation optical system for applying the laser beams emitted from the multi-mode fibers to a tissue of a patient. This laser therapy apparatus further includes a nonlinear optical element that is disposed between the laser source and the multi-mode fibers for substantially flattening the beam profile of the laser beams emitted from the multi-mode fibers, and that expands the spectrum width of the laser beams entering the multi-mode fibers by a self phase modulation effect.
