A data transfer device can adjust a phase of a clock signal with a simple configuration in a short period of time when transferring a digital data signal in synchronization with the clock signal. Accordingly, the data transfer device includes a data transfer line serially transferring the data signal, a clock transfer line transferring the clock signal, a decision unit deciding an adjustment amount by which the phase of the clock signal accompanying the data signal is shifted, the adjustment amount being used when transferring the data signal in synchronization with the clock signal, and a phase adjusting unit shifting the phase of the clock signal in accordance with the adjustment amount decided by the decision unit while keeping a frequency of the clock signal fixed.