A semiconductor device includes a first circuit element chip including a first surface on which a plurality of first electrodes are arranged, and a second circuit element chip including a first surface on which a plurality of second electrodes are arranged. The second circuit element chip is mounted on the first circuit element chip. The semiconductor device further includes an insulating film disposed on a side surface of the second circuit element chip and disposed between the first surfaces of the first and second circuit element chips. The semiconductor device still further includes a resin layer covering the second circuit element chip and the insulating film. Also, there is provided a manufacturing method of the semiconductor device which includes forming the insulating film after the second circuit element chip is mounted on the first circuit element chip.