To provide a semiconductor device including: first and second bus lines; a first buffer connected between the first and second bus lines; second and third buffers connected to the first bus line; fourth and fifth buffers connected to the second bus line; first to fourth banks connected via the first, second, and third buffers to the second bus line; fifth to eighth banks connected via the fourth and fifth buffers to the second bus line; and a data input/output unit connected to the second bus line. Transfer delay times of the fourth and fifth buffers are longer than transfer delay times of the first, second, and third buffers. Thereby, it becomes possible to eliminate differences in data transfer times resulting from differences in distances between far and near ends without causing significant increase in wire density, increase in power consumption, or the like.