A semiconductor package includes a semiconductor die, a redistribution circuit structure, a supporting structure and a protective layer. The redistribution circuit structure is located on and electrically coupled to the semiconductor die. The supporting structure is located on an outer surface of the redistribution circuit structure, wherein the supporting structure is overlapped with at least a part of the semiconductor die or has a sidewall substantially aligned with a sidewall of the semiconductor die in a vertical projection on the redistribution circuit structure along a stacking direction of the redistribution circuit structure and the supporting structure. The protective layer is located on the supporting structure, wherein the supporting structure is sandwiched between the protective layer and the redistribution circuit structure.