Automatic placement and routing apparatus for designing integrated circuit that controls its timing using multiple power supplies

An automatic placement and routing apparatus includes an initial power supply setting section for setting initial power supply potentials of cells; a placement and routing section for performing placement, global routing and detail routing of the cells according to a netlist and timing constraint information; a timing verification section for performing the timing verification of the specified paths according to the layout information at a particular stage of the placement and routing; and a power supply modification section for changing, when a cell having a timing problem is detected, the power supply potential of the cell. When the cell having a timing problem is detected, the placement and routing section optimizes the layout according to the change of the power supply potential of the cell, and the timing verification section performs the timing verification of the specified paths according to the layout information optimized.