To provide a logical operation circuit and a logical operation method which can
perform a logical operation using a ferroelectric capacitor. A logical operation
circuit 1 has ferroelectric capacitors CF1 and CF2 and a transistor
MP. The ferroelectric capacitor CF1 can retain a polarization state P1
corresponding to a logical operator. In an operation and storage process, a source
potential Vdd corresponding to first operation target data y1=1 and a ground
potential GND corresponding to second operation target data y2=0 are given
to a first terminal 3 and a second terminal 5, respectively, of the
ferroelectric capacitor CF1. The polarization state of the ferroelectric
capacitor CF1 is thereby shifted to P4. A residual polarization state
corresponding to the polarization state P4 is P2. The residual polarization
state changes (P1, P1, P2 or P1) depending on the combination
of y1 and y2 (0-0, 0-1, 1-0 and 1-1). In a reading process after
that, an output corresponding to the residual polarization state is obtained via
the transistor MP.