A mounting structure comprises at least one semiconductor device having solder bumps on a lower surface thereof as outer terminals and a flexible wiring board with wiring formed thereon. The semiconductor device is wrapped in a flexible wiring board; the mounting structure is provided with outer electrodes on both of a side on which the outer terminals of the semiconductor device are formed and an opposite side thereto; at least one wiring layer is formed on the flexible wiring board; and a supporting member is affixed between a lower surface of the semiconductor device on which the outer terminals are formed and the flexible wiring board.