A light emitting device, comprising: a substrate; a plurality of light emitting cells (P1∼PM) disposed on the substrate to be spaced apart from each other; and a connection wire (124-1-124-N) configured to electrically connect adjacent ones of the light emitting cells (P1∼PM), each of the light emitting cell having a rectangular shape when viewed from a top thereof, wherein each of the light emitting cells (P1∼PM) further comprises: a light emitting structure comprising a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer that are sequentially disposed on the substrate; a first electrode disposed on the first conductive type semiconductor layer; and a second electrode disposed on the second conductive type semiconductor layer, characterized in that a first separation distance in a first direction between first adjacent light emitting cells adjacent to each other without being connected by the connection wire (124-1-124-N) among the light emitting cells (P1∼PM) is smaller than a second separation distance in the first direction of second adjacent light emitting cells adjacent to each other with being connected by the connection wire (124-1-124-N) among the light emitting cells (P1∼PM), wherein the first separation distance corresponds to a separation distance between the first conductive type semiconductor layers of the first adjacent light emitting cells, and the second separation distance corresponds to a separation distance (D2-11) between the first conductive type semiconductor layers of the second adjacent light emitting cells, wherein widths in a second direction of the first and second adjacent light emitting cells are identical, the second direction being different from the first direction, wherein a cell length in the first direction of each of the first adjacent light emitting cells is greater than a cell length in the first direction of each of the second adjacent light emitting cells, by a difference between the first separation distance and the second separation distance, and wherein area of each of the first adjacent light emitting cells is wider than area of each of the second adjacent light emitting cells. a substrate; a plurality of light emitting cells (P1∼PM) disposed on the substrate to be spaced apart from each other; and a connection wire (124-1-124-N) configured to electrically connect adjacent ones of the light emitting cells (P1∼PM), each of the light emitting cell having a rectangular shape when viewed from a top thereof, wherein each of the light emitting cells (P1∼PM) further comprises: a light emitting structure comprising a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer that are sequentially disposed on the substrate; a first electrode disposed on the first conductive type semiconductor layer; and a second electrode disposed on the second conductive type semiconductor layer, a light emitting structure comprising a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer that are sequentially disposed on the substrate; a first electrode disposed on the first conductive type semiconductor layer; and a second electrode disposed on the second conductive type semiconductor layer, characterized in that a first separation distance in a first direction between first adjacent light emitting cells adjacent to each other without being connected by the connection wire (124-1-124-N) among the light emitting cells (P1∼PM) is smaller than a second separation distance in the first direction of second adjacent light emitting cells adjacent to each other with being connected by the connection wire (124-1-124-N) among the light emitting cells (P1∼PM), wherein the first separation distance corresponds to a separation distance between the first conductive type semiconductor layers of the first adjacent light emitting cells, and the second separation distance corresponds to a separation distance (D2-11) between the first conductive type semiconductor layers of the second adjacent light emitting cells, wherein widths in a second direction of the first and second adjacent light emitting cells are identical, the second direction being different from the first direction, wherein a cell length in the first direction of each of the first adjacent light emitting cells is greater than a cell length in the first direction of each of the second adjacent light emitting cells, by a difference between the first separation distance and the second separation distance, and wherein area of each of the first adjacent light emitting cells is wider than area of each of the second adjacent light emitting cells.