A circuit board includes a base plate, a first circuit layer, a first dielectric layer, and a light emitting element. The first circuit layer is disposed on the base plate. The first dielectric layer is disposed on the base plate and has plural openings. The first circuit layer is embedded in the first dielectric layer and exposes the openings. A Young's modulus of the first dielectric layer is greater than a Young's modulus of the base plate. The light emitting element is electrically connected to the first circuit layer through the openings.