In a data transfer apparatus a clock transmitting unit transmits a first clock to a target for data transfer that is situated at a distance from the data transfer apparatus, a data transmitting unit in synchronization with the first clock transmits data including a start signal to the target; a response receiving unit receives from the target a response having therein the start signal and outputs a first response based on the response received; a clock generating unit receives the first clock and generates a second clock based on the first clock; a response generating unit in synchronization with the second clock generates a second response based on the first response; and a selector selects any one of the first response and the second response depending on the distance.