The present invention provides a semiconductor laser excellent in the current injection efficiency. In an inner stripe type semiconductor laser according to the present invention, a p type cladding layer 309 has a superlattice structure composed of GaN layers and Al.sub.0.1Ga.sub.0.9N layers, which are alternately layered on each other. The p type cladding layer 309 has a portion of high dislocation density and a portion of low dislocation density. That is, the dislocation density is relatively low in a region directly above an opening of the current-confining region 308, whereas the dislocation density is relatively high in a region directly above a current-confining region 308.