In regard to a semiconductor device having a multilayered wiring board where a semiconductor chip is embedded inside, a technology which allows the multilayered wiring board to be made thinner is provided. A feature of the present invention is that, in a semiconductor device where bump electrodes are formed over a main surface (element forming surface) of a semiconductor chip embedded in a chip-embedded wiring board, an insulating film is formed over a back surface (a surface on the side opposite to the main surface) of the semiconductor chip. As a result, it becomes unnecessary to form a prepreg over the back surface of the semiconductor chip. Therefore, an effect of thinning the chip-embedded wiring board in which the semiconductor chip is embedded is obtained.