A light emitting diode comprising: a conductive support member; a reflective layer on the conductive support member; a light emitting structure on the reflective layer including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer between the first and second conductivity type semiconductor layers (130, 150); and an ohmic contact layer between the reflective layer and the second conductivity type semiconductor layer; a current blocking layer between the ohmic contact layer and the light emitting structure; and an electrode on the first conductivity type semiconductor layer, wherein the reflective layer comprises a recess portion, wherein the current blocking layer is vertically overlapped with the recess portion of the reflective layer, wherein a first distance (h1') satisfies 2·(Φ1+Φ2)+ Φ3 = N·2π±Δ1 with π/2≤Δ1≤π, and a second distance (h2') satisfies 2·(Φ1+Φ2') + Φ3 = N·2π±Δ2 with 0≤Δ2≤π/2, in which the Φ1 represents a phase change value when light vertically travelling passes through the second conductivity type semiconductor layer, the Φ2 represents a phase change value when the light passes through the ohmic contact layer and the current blocking layer, the Φ2' represents a phase change value when the light passes through the ohmic contact layer, the Φ3 represents a phase change value when the light is reflected by the reflective layer, and the N represents a natural number, wherein the first distance (h1') is a distance between the active layer and the reflective layer vertically corresponding to the current blocking layer in a first region (A'), wherein the second distance (h2') is a distance between the active layer and the reflective layer in a second region (B') other than the first region (A'), wherein the current blocking layer is vertically overlapping with the electrode, wherein a lateral width of the recess portion is same with a lateral width of the current blocking layer, and wherein the ohmic contact layer makes ohmic contact with the second conductivity type semiconductor layer while transmitting light. a conductive support member; a reflective layer on the conductive support member; a light emitting structure on the reflective layer including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer between the first and second conductivity type semiconductor layers (130, 150); and an ohmic contact layer between the reflective layer and the second conductivity type semiconductor layer; a current blocking layer between the ohmic contact layer and the light emitting structure; and an electrode on the first conductivity type semiconductor layer, wherein the reflective layer comprises a recess portion, wherein the current blocking layer is vertically overlapped with the recess portion of the reflective layer, wherein a first distance (h1') satisfies 2·(Φ1+Φ2)+ Φ3 = N·2π±Δ1 with π/2≤Δ1≤π, and a second distance (h2') satisfies 2·(Φ1+Φ2') + Φ3 = N·2π±Δ2 with 0≤Δ2≤π/2, in which the Φ1 represents a phase change value when light vertically travelling passes through the second conductivity type semiconductor layer, the Φ2 represents a phase change value when the light passes through the ohmic contact layer and the current blocking layer, the Φ2' represents a phase change value when the light passes through the ohmic contact layer, the Φ3 represents a phase change value when the light is reflected by the reflective layer, and the N represents a natural number, wherein the first distance (h1') is a distance between the active layer and the reflective layer vertically corresponding to the current blocking layer in a first region (A'), wherein the second distance (h2') is a distance between the active layer and the reflective layer in a second region (B') other than the first region (A'), wherein the current blocking layer is vertically overlapping with the electrode, wherein a lateral width of the recess portion is same with a lateral width of the current blocking layer, and wherein the ohmic contact layer makes ohmic contact with the second conductivity type semiconductor layer while transmitting light.