A light emitting device includes a light emitting chip which generates a first light having a first color, a first cavity layer disposed on the light emitting chip and which generates a second light having a second color and has a first refractive index, a second cavity layer disposed on the first cavity layer and which generates a third light having a third color and has a second refractive index, a first half mirror layer disposed between the first cavity layer and the light emitting chip and which reflects at least a portion of the second light, a second half mirror layer disposed between the first cavity layer and the second cavity layer and which reflects at least a portion of the third light, and a third half mirror layer disposed on the second cavity layer and which transmits the first light.