A semiconductor laser device comprises a substrate having an n-type buffer layer, a semiconductor laser element and auxiliary element, provided side by side on the buffer layer. The semiconductor laser element includes a mesa portion having a p-type low resistant semiconductor region provided above the buffer layer, an active region consisting of a semiconductor formed on the buffer layer and low resistant region, a pair of buried portions integrally formed with the low resistive region and formed on and contiguous to opposite sides of the active region in the width direction. A lateral hole is provided between the buffer layer and low resistive region on the side of buried portion. The auxiliary element includes a high resistive regions integrally formed with the low resistant region and positioned on the sides of low resistive region.