PURPOSE: To constitute the data exchange device which has large data processing capacity on the whole by using data communication modules with relatively small data processing capacity by dispersing traffic to numbers of communication media and relaying their buses through numbers of data communication modules.

CONSTITUTION: Horizontal buses H1, H2...Hy composed of plural data transmission media and vertical buses V1, V2...Vx composed of plural data transmission media are arranged logically in a lattice shape. Then, data communication modules 11, 21...xy are connected to horizontal buses and vertical buses at respective lattice points. Those modules 11...xy function to perform communication between equipped circuits and the buses H1...Hy and V1...Vx through equipped circuit interface parts 310, 320...3n0, communication between the horizontal buses H1...Hy and vertical buses V1...Vn, and mutual communication among eqipped circuits 311, 312, 322...3n1, 3n2 through interface parts 310...3n0.