A light-emitting device comprises: a light-emitting stack having an active layer; a transparent insulating layer on the light-emitting stack; and an electrode structure having a first electrode on the transparent insulating layer; wherein a surface area of a surface of the first electrode distal from the transparent insulating layer is smaller than a surface area of a surface of the transparent insulating layer distal from the light-emitting stack, the refractive index of the transparent insulating layer is between 1 and 3.4 both inclusive, and the transmittance of the transparent insulating layer is greater than 80%.