Abstract: A semiconductor device includes an electrical insulating layer with superior heat resistance, heat dissipation, and durability, and which is manufactured through a process with good cost performance and process performance. In a semiconductor device including a first substrate to which a semiconductor chip is mounted directly or indirectly, and a white insulating layer formed on a surface of the first substrate and functioning as a reflecting material, the semiconductor chip is an LED, at least the surface of the first substrate is made of a metal, and a stacked structure of the white insulating layer and a metal layer is formed by coating a liquid material, which contains SiO2 in the form of nanoparticles and a white inorganic pigment, over the surface of the first substrate and baking the coated liquid material.