The light-emitting device of the disclosure includes at least one LED chip and a mounting substrate. The mounting substrate includes: a ceramic substrate; a reflection layer situated on a second surface on the opposite side of the ceramic substrate from a first surface; and a gas barrier layer covering the reflection layer. The LED chip is bonded to the first surface of the ceramic substrate. The ceramic substrate has light diffusion and transmissive properties and has a plan size larger than a plan size of the LED chip. The reflection layer has a plan size smaller than a plan size of the ceramic substrate and is formed so as to cover an area larger than a projected area of the LED chip on the second surface of the ceramic substrate.