To transmit plural ATM(asynchronous transfer mode) cells from one output highway without causing any delay.

This device is provided with ATM switch means 621-624 with plural faces for operating the switching of an ATM cell based on a tag at each cross point of plural inputs and plural outputs, and is further provided with plural outputting means 641-644 and 661-664 for each of plural output highways for multiplying ATM cells supplied from the ATM switching means on the plural faces, and for transmitting it to each output highway. Thus, the ATM cell inflowing from one input highway can be copied and outputted from the plural output highways, and the plural copied ATM cells can be transmitted from one output highway. Therefore, the circuit scale can be miniaturized.