A laser module includes: one or more semiconductor laser elements which emit one or more laser beams; an optical fiber which has a light-entrance end face; and an optical condensing system which is constituted by one or more optical components and makes the one or more laser beams converge at the light-entrance end face of the optical fiber. In the laser module, at least one of one or more light-entrance surfaces and one or more light-output surfaces of the one or more optical components is exposed to air, and the one or more laser beams realize an optical power density of 15 W/mm.sup.2 or lower, or 60 to 800 W/mm.sup.2 at the at least one of the one or more light-entrance surfaces and the one or more light-output surfaces.