The present invention relates to a dual-laser device having an optical switch, which outputs a plurality of wavelength bands using a single laser generating unit. The laser device used for treating skin comprises: a laser generating unit which generates a light source; a first medium unit which forms a first light source by exciting the light source; an optical switch unit which converts the first light source formed through the first medium unit into predetermined output; and a second medium unit which forms a second light source by being connected to any one end of the optical switch unit and exciting the first light source.
