PURPOSE: To obtain a resonator plane for an etching laser which provides excellent mass producibility and a high yield and which can be applied to an existing semiconductor laser formed on a crystal which has a (100) face as a surface by a method wherein vapor phase etching with etching gas which does not contain or contains a very little V-group elements is employed.

CONSTITUTION: A semiconductor laser wafer consists of a semiconductor substrate 500 and a double hetero structure which is formed on the substrate 500 and which consists of cladding layers 20 and 30 and an activation layer 10 sandwiched between the layers 20 and 30. A stripe shape etching resistant film 100 is formed on the semiconductor laser wafer along the crystal direction <011>. Then the semiconductor laser wafer 300 is put on a susceptor 210 in a reaction tube 200 and exposed in an etching atmosphere such as hydrochloric acid gas, TBr, Cl2 or Br2 while being heated by an RF coil 250 so that the crystal outside the region covered with the etching resistant film 100 is etched. In this process, the etching gas atmosphere is controlled in such a manner that the etching gas does not contain the gas with a molecular formula in which a V-group element, one of the elements composing the crystal, is contained or that a concentration of the V-group element gas is lower than the etching gas concentration.