The present invention relates to a compound semiconductor substrate and a method for manufacturing the same. The present invention provides the manufacturing method which coats spherical balls on a substrate, forms a metal layer between the spherical balls, removes the spherical balls to form openings, and grows a compound semiconductor layer from the openings. According to the present invention, the manufacturing method can be simplified and grow a high quality compound semiconductor layer rapidly, simply and inexpensively, as compared with a conventional ELO (Epitaxial Lateral Overgrowth) method or a method for forming a compound semiconductor layer on a metal layer. And, the metal layer serves as one electrode of a light emitting device and a light reflecting film to provide a light emitting device having reduced power consumption and high light emitting efficiency.