To improve safety, when using a laser beam source device.

A part of infrared laser beam output from a semiconductor laser device 100a and entering a second higher harmonic generating element 110 is output from the second higher harmonic generating element 110, in such a state that its wavelength is not changed. Since the laser beam output from the second higher harmonic generating element 110 is spread in radial form, a part of the laser beam output from the second higher harmonic generating element 110 that advances without entering a resonator 120 is reflected on the side surface of a cover 200 and enters the inside of a tubular member (infrared laser beam 303). Since the tubular member 210 is formed of a material which absorbs infrared light; and since a part of the light, such as laser beams 301 and 303, entering an aperture part 201 deviated by predetermined angles (1 and 2) in a direction (direction of the optical axis) where visible light is partially emitted from the aperture part 201 to the outside is, at least absorbed each time the light strikes the side surface of the tubular member 210, the infrared light is restrained from leaking to the outside.