A semiconductor device manufacturing method includes stacking a second semiconductor chip on a first surface of a first semiconductor chip such that the at bump electrode overlies the position of a first through silicon via in the first semiconductor chip, stacking a third semiconductor chip on the second semiconductor chip such that a second bump electrode on the second semiconductor chip overlies the position of a second through silicon via in the third semiconductor chip to form a chip stacked body, connecting the first and second bump electrodes of the chip stacked body to the first and the second through silicon vias by reflowing the bump material, placing the chip stacked body on the first substrate such that the first surface of the first semiconductor chip faces the second surface, and sealing the second surface and the first, second, and third semiconductor chips with a filling resin.