A data transfer device controls data transfer performed through a bus capable of separately processing a request and a response. The data transfer device include a plurality of access control units that produce a data transfer process according to the request; and an arbitration unit that performs arbitration between the requests issued by the plurality of access control units so as to determine a request to be accepted among those requests. The arbitration unit sets an arbitration prohibited period in which the arbitration is prohibited for a designated period and accepts only the request issued by a designated access control unit among the plurality of access control units during the arbitration prohibited period.