We have developed a new surface treatment, Mgbright, which produces a luster on AZ31 magnesium alloy surfaces. The treatment consists of a chemical process and a coating process, and the primary characteristics are that of developing a luster on AZ31 magnesium alloy and imparting a high resistance to corrosion. When Mgbright was applied, the value of surface roughness, Ra, required for developing luster was 1.5 µm. As the target Ra value of press-formed articles was set to less than 1.5 µm, mass-production press-forming was tested by means of the 100,000 times square-cup drawing method, and the target was achieved. We applied the Mgbright treatment techniques and the square-cup drawing test, and produced a laptop computer chassis.