A method of manufacturing a semiconductor light emitting device is provided. The method includes forming a first region of a lower semiconductor layer on a substrate, etching an upper surface of the first region using at least one gas used in forming the first region, in-situ in a chamber in which a process of forming the first region has been performed, forming a second region of the lower semiconductor layer on the first region, forming an active layer on the lower semiconductor layer, and forming an upper semiconductor layer on the active layer.