PURPOSE: To exchange cells subject to concatenation multiplex by providing a cell queue corresponding to a number of a 3rd switch group to each switch of a 1st switch group applying exchange connection of an input cell.

CONSTITUTION: Four F switches 102, four S switches 103 and four T switches 104 applying exchange connection to an input cell are formed to be 3-stage configuration to be expanded to 16×16 switches. A cell transmission arbitration circuit 101 arbitrates a cell transmission number requested from each of the F switches so as not to cause internal conflict and gives a transmission enable signal to each of the F switches. Then a queue of the F switches 102 is managed for each number of the T switches. Thus, large scale cell switches of 3-stage configuration is built up and cells subject to concatenation multiplex are exchanged.