The main internal part of the central processing unit CPU is configured of a CMOS circuit, i.e. a circuit constituted of pMOS and nMOS. The CMOS circuit mainly constituting the central processing unit CPU includes (not shown) a CMOS static logic circuit, a statically operable CMOS static circuit such as a CMOS static flip-flop, and a CMOS dynamic circuit for performing precharging of signal output