A semiconductor package may include a package substrate, a first interposer substrate mounted on the package substrate, and a first semiconductor chip disposed on the first interposer substrate. The first interposer substrate may include a first base layer, a second base layer disposed on the first base layer, circuit patterns provided in each of the first base layer and the second base layer, and an integrated device embedded in the first base layer and connected to at least one of the circuit patterns. A top surface of the first base layer may contact a bottom surface of the second base layer.