A light emitting device according to an embodiment includes a substrate; first to Mth light emitting cells (where M is a positive integer of two or more) which are arranged on the substrate so as to be spaced apart from each other; and first to (M−1)th interconnection wires which electrically connect the first to Mth light emitting cells in series, wherein an mth light emitting cell (where 1≤m≤M) includes a first conductive type semiconductor layer, an active layer and a second conductive type semiconductor layer, which are sequentially arranged on the substrate, and wherein an nth interconnection wire (where 1≤n≤M−1) interconnects the first conductive type semiconductor of the nth light emitting cell with the second conductive type semiconductor of the (n+1)th light emitting cell, and has a plurality of first branch wires which are spaced apart from each other.