To easily control synchronism between a body of a superconducting single magnetic flux quantum circuit and a latch type driver in the superconducting single magnetic flux quantum circuit having the latch type driver as a driver for data output.

A data transfer circuit for simultaneously transferring data D1-D4 outputted sequentially from a body 9 of the superconducting single magnetic flux quantum circuit to latch type drivers 12-1 to 12-4 is composed of a demultiplexer 10, RS flip-flops 11-1 to 11-4, an SFQ pulse multiplexing circuit 13, a clock generating source 14 and a clock generating circuit 15.