Data transfer bus charging/discharging current is reduced in a semiconductor memory device. In a data transfer device that sequentially transfers bit sequences in parallel through a plurality of buses from a transmit unit 10 to a receive unit 20, the transmit circuit 10 includes a flag generation circuit 11 and an encoding circuit 12. The flag generation circuit 11 generates a flag indicating whether bit inversion has occurred in consecutive bits in each of the bit sequences to be transferred through the buses and transmits the generated flag to the receive unit 20. The encoding circuit 12 encodes the bit sequences based on the flag, for transmission to the receive unit 20. The receive unit includes a decoding circuit 21 that decodes the bit sequences based on the bit sequences and the flag.