A redistribution structure includes a first dielectric layer and a first redistribution circuit layer. The first dielectric layer includes a first via opening. The first redistribution circuit layer is disposed on the first dielectric layer and includes a via portion filling the first via opening and a circuit portion connecting the via portion and extending over the first dielectric layer. A maximum vertical distance between an upper surface of the via portion and an upper surface of the circuit portion is substantially equal to or smaller than 0.5 μm.