Disclosed is a substrate for LED mounting, which comprises a heat conductive layer (a hest conductive sheet (10)) that is formed from a composition that contains a boron nitride powder and a fluorine resin. The fluorine resin contains a polytetrafluoroethylene. The heat conductive layer has a heat conductivity of not less than 2 W/(m·K). The heat conductive layer has a reflectance of not less than 0.80 at wavelengths of 380 nm, 470 nm and 650 nm.
