To obtain a double storage capacity from the same cell area as before by memorizing a binary data in a paraelectric component and memorizing another binary data in a ferroelectric component, to memory cells comprised of ferroelectric capacitors.

When a film thickness of a ferroelectric material is expressed by (d) and an electric field not lower than Vc=Ec.d is applied thereon, polarization is reversed. In the equation, Ec is a coercive electric field and is determined by kind of the ferroelectric material and its film quality. Data can be stored by utilising polarization from the fact that an existence of a bi-stable state is indicated by the points A and C when the power supply for this memory is interrupted. Thus, a memory cell MC is a semiconductor storage device featuring to hold a binary data utilizing a paraelectric component of a ferroelectric material, featuring also to hold another binary data by utilizing a ferroelectric component, and featuring to hold the quaternary data by using these two kinds of the binary data. As a result, a double storage capacity can be obtained from the same cell area as before.