A printed circuit board according to an embodiment of the present invention includes a substrate including a first metal layer, a second metal layer formed on one surface of the first metal layer, and a third metal layer formed on the other surface of the first metal layer, an insulating layer formed on the second metal layer, and a circuit pattern formed on the insulating layer. A cavity configured to accommodate a light emitting element package is formed in the insulating layer. A thermal conductivity of the first metal layer is greater than thermal conductivities of the second metal layer and the third metal layer.