A semiconductor package includes an upper substrate having a first surface and a second surface which are opposite to each other, a semiconductor chip on the first surface of the upper substrate, a buffer layer on the second surface of the upper substrate, a mold layer between the second surface of the upper substrate and the buffer layer, a plurality of through-electrodes penetrating the upper substrate and the mold layer, an interconnection layer between the first surface of the upper substrate and the semiconductor chip and configured to electrically connect the semiconductor chip to the plurality of through-electrodes, and a plurality of bumps disposed on the buffer layer, spaced apart from the mold layer, and electrically connected to the plurality of through-electrodes. The mold layer includes an insulating material of which a coefficient of thermal expansion is greater than that of the upper substrate.