A heat radiating substrate having strengthened insulation resistance and heat conductivity, and a manufacturing method thereof. The method for manufacturing a heat radiating substrate includes: preparing a metal substrate; performing an anodizing process on the metal substrate to form an anodic oxidation layer; filling surface pores of the anodic oxidation layer with an insulating material; and forming a metal wiring layer on the anodic oxidation layer. High insulation resistance and heat conductivity can be obtained by filling surface pores formed in an anodizing process with an insulating material.