In a data transfer system in which wireless data transmission is carried out between a first device and a second device that each has a UWB wireless device, the data transfer system includes a ranging unit that is provided in the UWB wireless device of at least one of the first and second devices and measures a distance to the other of the first and second devices; a distance determination unit that determines, based on a measurement result by the ranging unit, whether or not the distance between the first and second devices has been within such a predetermined range that a predetermined transmission rate and a predetermined transmission quality are obtained by UWB communication; and a data transfer unit that executes data transmission between the first and second devices in response to a determination by the distance determination unit that the distance between the first and second devices has been within the predetermined range.