Abstract: A semiconductor light emitting device easily controlled in reflectance of its cavity edges has formed on the cavity edges of its laser cavity rugged structures including elongated concave portions extending substantially in parallel with bonded surfaces of semiconductor layers forming the laser cavity. The laser cavity is made by sequentially stacking on a substrate an n-type AlGaN cladding layer, n-type GaN optical guide layer, InGaN active layer, p-type GaN optical guide layer and p-type AlGaN cladding layer. The rugged structure is made by first making the cavity edges by etching and then processing the cavity edges by wet etching so that the cavity edges are selectively excavated due to differences in chemical property among semiconductor layers forming the laser cavity caused by differences in composition among them.