A semiconductor integrated circuit of an aspect of the present invention having a CMOS logic gate including a first MOS transistor of a first conductivity type and a second MOS transistor of a second conductivity type, has a first MOS transistor region in which the first MOS transistor is formed, and a 2ath MOS transistor region and a 2bth MOS transistor region, in each of which the second MOS transistor is formed, separately arranged to be in contact with a first side of said first MOS transistor region and a second side opposite to the first side.