A light source used for illumination provides favorable heat dissipation properties while suppressing the lowering of the efficiency of light emission. The light source includes a mount substrate, an LED 23 mounted on the mount substrate and a silicon resin mold containing phosphor particles that convert the wavelength of light emitted from the LED 25. The mount substrate includes a metal substrate 23 coated with a ceramic layer 24 containing light-transmissive or highly reflective ceramic particles.