PURPOSE: A nitride semiconductor layer growth method is provided to produce a high quality free-standing nitride semiconductor substrate by preventing crack by tensile stress. CONSTITUTION: A substrate (1) is prepared in a reactor. A nitride semiconductor is laminated onto the substrate prepared in the reactor. The substrate is etched in the reactor. Additional nitride semiconductors are laminated on the laminated nitride semiconductor. The additional nitride semiconductor lamination is progressed with a thickness over 10 micro meter.
