The present invention relates to a light emitting device and a method of manufacturing the light emitting device. According to the present invention, the light emitting device comprises a substrate, an N-type semiconductor layer formed on the substrate, and a P-type semiconductor layer formed on the N-type semiconductor layer, wherein a side surface including the N-type or P-type semiconductor layer has a slope of 20 to 80° from a horizontal plane. Further, the present invention provides a light emitting device comprising a substrate formed with a plurality of light emitting cells each including an N-type semiconductor layer and a P-type semiconductor layer formed on the N-type semiconductor layer, and a submount substrate flip-chip bonded onto the substrate, wherein the N-type semiconductor layer of one light emitting cell and the P-type semiconductor layer of another adjacent light emitting cell are connected to each other, and a side surface including at least the P-type semiconductor layer of the light emitting cell has a slope of 20 to 80° from a horizontal plane. Further, the present invention is provides a method of manufacturing the light emitting device. Accordingly, there is an advantage in that the characteristics of a light emitting device such as luminous efficiency, external quantum efficiency and extraction efficiency are enhanced and the reliability is secured such that light with high luminous intensity and brightness can be emitted.