A basic cell of the present invention comprises a plurality of wires which
constitute a wiring route of 90.degree., one ends of the plurality of
wires being on one of opposite sides, and the other ends of the plurality
of wires being on the other one of the opposite sides, wherein: each of
the one ends of the plurality of wires is point-symmetric to any of the
other ends of the plurality of wires with respect to the center of the
area of the basic cell; and routes of the plurality of wires do not cross
one another.