A light emitting device package comprising: a substrate; a first light emitting chip disposed on the substrate; a plurality of second light emitting chips disposed on the outer circumference of the first light emitting chip; and a lens formed on the first and the second light emitting chips (120, 130), wherein the lens includes a side and a curved surface wherein the side is cylindrically formed on the substrate perpendicular to the substrate and the curved surface is hemispherically formed on the side, wherein the lens satisfies the following relational expression, z = c r 2 1 + 1 − 1 + K c 2 r 2 where "Z" represents a sag of the lens defined as the displacement of the lens curved surface from the centre of the lens in a direction perpendicular to the substrate surface at an edge of the lens; "K" represents a conic constant of the lens; "r" represents a radius of the lens; and "C" represents 1/R where R is the radius of curvature of the lens, wherein the conic constant "K" has a range from -10.50 to 0.00, or wherein the lens satisfies the following relational expression LWT / LRcT = a ratio of from 1.2 to 3.0, where "LWT" represents a sag of the lens defined as the thickness of the lens in a direction perpendicular to the substrate, at the center of the first light emitting chip; and "LRcT" represents a sag of the lens defined as the thickness of the lens in a direction perpendicular to the substrate, at the center of each second light emitting chip, or wherein the lens satisfies the following relational expression LWT / LReT = a ratio of from 1.2 to 3.0, where "LWT" represents a sag of the lens defined as the thickness of the lens in a direction perpendicular to the substrate, at the center of the first light emitting chip; and "LReT" represents a sag of the lens defined as the thickness of the lens in a direction perpendicular to the substrate, at the outer edge of each second light emitting chip, characterised in that, the radius of curvature R of the lens has a range from 1.90 to 4.70 mm and wherein the "C" has a range from 0.21 to 0.53 mm -1, and wherein a thickness of the first light emitting chip is larger than a thickness of each of the second light emitting chips, and wherein the thickness of each of the second light emitting chips is larger than the thickness (or height) of the side of the lens or a thickness of each of the second light emitting chips is larger than a thickness of the first light emitting chip, and wherein the thickness of the first light emitting chip is larger than the thickness (or height) of the side of the lens. a substrate; a first light emitting chip disposed on the substrate; a plurality of second light emitting chips disposed on the outer circumference of the first light emitting chip; and a lens formed on the first and the second light emitting chips (120, 130), wherein the lens includes a side and a curved surface wherein the side is cylindrically formed on the substrate perpendicular to the substrate and the curved surface is hemispherically formed on the side, wherein the lens satisfies the following relational expression, where "Z" represents a sag of the lens defined as the displacement of the lens curved surface from the centre of the lens in a direction perpendicular to the substrate surface at an edge of the lens; "K" represents a conic constant of the lens; "r" represents a radius of the lens; and "C" represents 1/R where R is the radius of curvature of the lens, wherein the conic constant "K" has a range from -10.50 to 0.00, or wherein the lens satisfies the following relational expression where "LWT" represents a sag of the lens defined as the thickness of the lens in a direction perpendicular to the substrate, at the center of the first light emitting chip; and "LRcT" represents a sag of the lens defined as the thickness of the lens in a direction perpendicular to the substrate, at the center of each second light emitting chip, or wherein the lens satisfies the following relational expression where "LWT" represents a sag of the lens defined as the thickness of the lens in a direction perpendicular to the substrate, at the center of the first light emitting chip; and "LReT" represents a sag of the lens defined as the thickness of the lens in a direction perpendicular to the substrate, at the outer edge of each second light emitting chip, characterised in that, the radius of curvature R of the lens has a range from 1.90 to 4.70 mm and wherein the "C" has a range from 0.21 to 0.53 mm -1, and wherein a thickness of the first light emitting chip is larger than a thickness of each of the second light emitting chips, and wherein the thickness of each of the second light emitting chips is larger than the thickness (or height) of the side of the lens or a thickness of each of the second light emitting chips is larger than a thickness of the first light emitting chip, and wherein the thickness of the first light emitting chip is larger than the thickness (or height) of the side of the lens.