An objective is to provide a reliability-improved semiconductor device in which heat radiation characteristics are superior, and warpage of the semiconductor device occurring due to heat generation of a semiconductor chip or to varying of the usage environment is also suppressed. The semiconductor device is provided that includes a thermal-conductive sheet 3 formed on a base board 4, including thermal-conductive resin 6, a heat sink 2 provided on the base board 4 through the thermal-conductive sheet 3, a semiconductor chip 1 mounted on the heat sink 2, and a ceramic-embedded region 31 selectively provided in a region of the thermal-conductive sheet 3 under the semiconductor chip 1, including a ceramic component 5. In this semiconductor device, superior thermal conductivity can be ensured, and warpage and peeling in the semiconductor device occurring due to heat generation of the semiconductor chip or to varying of the usage environment can also be reduced.