PURPOSE: To increase the density while stabilizing electrical characteristics by forming a conductor layer to which fixed potential is given between an MISFET of the first layer and an MISFET of the second layer.

CONSTITUTION: A semiconductor layer 3 is made up on an SiO2 film 2 on the surface of an Si substrate 1, and a source region S1, a drain region D1 and an active region C1 of an MISFET are built up to the semiconductor layer 3. A gate electrode 5 is formed on the active region C1 through a gate SiO2 film 4. An SiO2 film 6 and a conductor layer 7 consisting of polycrystalline Si are further made up on the semiconductor layer 3. Fixed potential such as earth potential is given to the conductor layer 7. A semiconductor layer 9 of the second layer is built up through an SiO2 film 8, and a source region S2, a drain region D2 and an active region C2 of an MISFET are formed to the semiconductor layer 9.