A light-emitting device may include a substrate, a light source arranged on the substrate, and a cover part spaced a certain distance apart from the light source and transmitting light emitted from the light source to outside. The cover part includes a first part, converting wavelengths of a part of light in light emitted from the light source and having different thicknesses at least in two different light-emitting directions of the light source, and a second part, having different thicknesses in the two different light-emitting directions to compensate the thicknesses of the first part.