Provides an IC chip for high frequency region, particularly a packaged substrate in which no malfunction or error occurs even if 3GHz is exceeded. Conductive layer 34P on core substrate 30 is formed in the thickness of 30[mu]m and a conductor circuit 58 on interlayer resin insulation layer 50 is formed in the thickness of 15[mu]m. By thickening the conductive layer 34P, the volume of the conductor can be increased and resistance can be reduced. Further, by using the conductive layer 34 as a power source layer, the capacity of supply of power to an IC chip can be improved.