A light emitting device comprising: a conductive layer having a first conductive layer (240,240A) and a second conductive layer; a support member disposed under the second conductive layer; an electrode (20,110,220); a light emitting structure layer (10,235) disposed between the electrode and the conductive layer and comprising a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; a passivation layer disposed around a lower surface of the second conductivity type semiconductor layer, and a light guide layer (30,31,30B,30C,55,65,75,85,95,105,125,135,225) between the first conductivity type semiconductor layer and the electrode, wherein the electrode comprises a first portion contacting at least one surface of a periphery of the light guide layer and a second portion extending from the first portion toward a top surface of the light guide layer, wherein the electrode has a width of a top surface greater than a width of a lower surface, wherein the light guide layer comprises an inner surface contacting the electrode and an outer surface non-contacting the electrode at the periphery of the light guide layer, wherein the light guide layer has a thickness less than that of the electrode and a width of a first direction less than that of a first direction of the electrode, wherein the light guide layer comprises a first layer having a first refractive index between the first conductivity type semiconductor layer and the electrode and a second layer having a second refractive index less that the first refractive index between the first layer and the electrode, wherein the first layer is formed of a transmissive conductive oxide material and the second layer is formed of an insulating material, wherein the passivation layer and the first conductive layer (240,240A) are disposed under the second conductivity type semiconductor layer, wherein the support member is made of a conductive material, wherein the electrode includes a pad, and wherein a portion of a top surface of the first conductivity semiconductor layer has a roughness. a conductive layer having a first conductive layer (240,240A) and a second conductive layer; a support member disposed under the second conductive layer; an electrode (20,110,220); a light emitting structure layer (10,235) disposed between the electrode and the conductive layer and comprising a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; a passivation layer disposed around a lower surface of the second conductivity type semiconductor layer, and a light guide layer (30,31,30B,30C,55,65,75,85,95,105,125,135,225) between the first conductivity type semiconductor layer and the electrode, wherein the electrode comprises a first portion contacting at least one surface of a periphery of the light guide layer and a second portion extending from the first portion toward a top surface of the light guide layer, wherein the electrode has a width of a top surface greater than a width of a lower surface, wherein the light guide layer comprises an inner surface contacting the electrode and an outer surface non-contacting the electrode at the periphery of the light guide layer, wherein the light guide layer has a thickness less than that of the electrode and a width of a first direction less than that of a first direction of the electrode, wherein the light guide layer comprises a first layer having a first refractive index between the first conductivity type semiconductor layer and the electrode and a second layer having a second refractive index less that the first refractive index between the first layer and the electrode, wherein the first layer is formed of a transmissive conductive oxide material and the second layer is formed of an insulating material, wherein the passivation layer and the first conductive layer (240,240A) are disposed under the second conductivity type semiconductor layer, wherein the support member is made of a conductive material, wherein the electrode includes a pad, and wherein a portion of a top surface of the first conductivity semiconductor layer has a roughness.