A redistribution structure includes a first dielectric layer, a pad pattern, and a second dielectric layer. The pad pattern is disposed on the first dielectric layer and includes a pad portion and a peripheral portion. The pad portion is embedded in the first dielectric layer, wherein a lower surface of the pad portion is substantially coplanar with a lower surface of the first dielectric layer. The peripheral portion surrounds the pad portion. The second dielectric layer is disposed on the pad pattern and includes a plurality of extending portions extending through the peripheral portion.