To attain miniaturization, lowering in height, and further reduction of noise by reducing the influence of noise generated by a bus line and by the shortest distance wiring of the bus line connecting between semiconductor ICs. The module 100 with a built-in semiconductor IC is equipped with a multilayer substrate 101 having a first and second insulating layer 101a, 101b, and a controller IC 102 and memory IC 103 embedded in the multilayer substrate 101. A wiring layer 104 is provided in the internal layer of the multilayer substrate 101. A part of the wiring layer 104 constitutes a bus line 104X, and connection is made between the controller IC 102 and the memory IC 103 by the bus line 104X. The controller IC 102 and the memory IC 103 is embedded in the second insulating layer 101b. In the surface of the first and second insulating layer 101a, 101b, a first and second ground layers 105a, 105b are provided respectively. |