A data transfer apparatus for simplifying a module structure for controlling a connected data recording apparatus and improving the processing efficiency. A control code issued by a common application module having a main purpose of check-out/check-in is made a control code corresponding to a device connected by a conversion module and transmitted via a device driver. Moreover, for example, a control code issued by a local application module having a main purpose of controlling processing depending on a device connected shares the aforementioned device driver. For example, the local application module issues a control code in a state matched with a control code format converted by the conversion module. Alternatively, the local application module issues a local control code by indicating issuance of a local control code of a format different from the control code format converted by the conversion module.