Disclosed herein is a light emitting device. The light emitting device is provided to include a light emitting structure, a first electrode pad, a second electrode pad and a heat dissipation pad, and a substrate on which the light emitting diode is mounted. The substrate includes a base; an insulation pattern formed on the base; and a conductive pattern disposed on the insulation pattern. The base includes a post and a groove separating the post from the conductive pattern. An upper surface of the post is placed lower than an upper surface of the conductive pattern, the heat dissipation pad contacts the upper surface of the post, and the first electrode pad and the second electrode pad contact the conductive pattern. With this structure, the light emitting device has excellent properties in terms of electrical stability and heat dissipation efficiency.