PURPOSE: To improve the efficiency of an output from laser beams, and to stabilize the output by using a light-emitting element in which neodymium yttrium aluminum garnet and neodymium yttrium aluminate are combined.

CONSTITUTION: A semiconductor laser element 1 is formed of neodymium yttrium aluminum garnet (Nd:YAG) having a wavelength of 808nm of excitation light 9. A light-emitting element 4 is composed of the combination of a neodymium yttrium aluminum garnet (Nd:YAG) rod 5 having absorption peaks in wavelengths of 808nm and 805nm and a neodymium yttrium aluminate (Nd: YAlO3) rod 6 having absorption peaks in wavelengths of, 807nm and 802nm. Consequently, the light-emitting element 4 having the absorption peaks extending over a wide range from the wavelength of 802nm to the wavelength of 808nm is acquired regarding synthesized transmittance, and the temperature rise of the semiconductor laser element 1 is inhibited by using a Peltier element 8, thus suppressing the change of the wavelength of excitation light 9. Accordingly, the efficiency of an output from laser beams is improved, and the output is stabilized.