PURPOSE: To contrive the large scale integration by a method wherein pad electrodes are provided at the inside and outside of a baseplate, and these electrodes are connected by electrical conductive parts which penetrate the base plates, and plural number of such base plates are stacked one upon another.

CONSTITUTION: Pad electrodes 2aW6a are formed at the position corresponding each other of the surface and the inside of the first, the second and the third semiconductor base plates 1aW1c. The surface and the inside pad electrodes 2a, 6a, 2b, 6b, 2c, 6c are connected in the electrical conductive parts 7aW7c. When base plates 1aW1c are laminated, between pad electrodes 1a, 6a etc. are adhered and laminated by low melting solder. Since this device is stacked and solidified, the integration is possible without enlarging the plane expansion.