Within a semiconductor laser device, mounting a semiconductor laser element array of multi-beam structure on a sub-mount, the semiconductor laser element array of multi-beam structure comprises one piece of a semiconductor substrate 11; a common electrode 1, which is formed on a first surface of the semiconductor substrate; a semiconductor layer 2, which is formed on the other surface of the semiconductor substrate, and has a plural number of light emitting portions 7 within an inside thereof; a plural number of anode electrodes 3 of a second conductivity type, which are formed above the plural number of light emitting portions, respectively; and a supporting portion 25, which is provided outside a region of forming the light emitting portions, wherein on one surface of the sub-mount is connected an electrode 3 of the semiconductor laser element array through a solder 4, and that solder 4 is formed to cover a supporting portion and an electrode neighboring thereto, and further on the electrode 3 is formed a groove portion 9 between the supporting portion 25 neighboring and the light emitting portions 7.