A method of manufacturing a surface emitting laser includes: forming a mesa by performing etching on a lower reflector layer, an active layer, and an upper reflector layer; forming a current narrowing layer by oxidizing a part of the upper reflector layer; exposing a substrate by performing etching on the lower reflector layer, the active layer, and the upper reflector layer, using a chlorine-containing gas; cleaning the substrate; performing heat treatment on the substrate; forming an insulating film covering a surface of the substrate; forming an electrode on the lower reflector layer and the upper reflector layer; and performing heat treatment on the substrate, wherein a temperature in the first heat treatment is lower than a temperature in the forming the current narrowing layer.