Abstract: A semiconductor integrated circuit includes a substrate which has a predetermined width in a first direction and a predetermined length in a second direction which is approximately perpendicular to the first direction, a plurality of cells which are provided on the substrate and are grouped into a plurality of generally rectangular unit blocks, where each of the unit blocks are made up of cells having mutually different widths in the first direction but a common length in the second direction, first interconnections for supplying at least one power source voltage to the cells, where the first interconnections are provided independently for each unit block so as to supply the power source voltage in common to each of the cells making up the unit block, a row of first terminals of the cells, within each unit block, arranged in the first direction, a row of second terminals of the cells, within each unit block, arranged in the first direction an interconnection region at least including a region which is defined