A semiconductor device comprises a first external terminal having a first size, a plurality of second external terminals each having a second size smaller than the first size, an external terminal area in which the first external terminal and the second external terminals are arranged, and a plurality of wires connecting between the second external terminals and a plurality of circuits formed adjacent to the external terminal area and corresponding to the second external terminals. The second external terminals and the wires constitute a plurality of interfaces. Each of the interfaces includes at least one adjustment portion that adjusts a time constant of the wire so that the wires have the same time constant. At least part of the adjustment portions is located in a margin area produced in the external terminal area by a difference between the first size and the second size.