To provide a data processor, a program for use therein and a medium storing that program in which a trouble that facsimile data cannot be transmitted at a specified transmission date because communication cannot be performed normally between a personal computer and a facsimile at the specified transmission date due to radio communication employed in communication between the personal computer and the facsimile can be prevented.

Upon confirming selection of a radio communicating section 25, a control section 23 receives a storable signal from a FAX 1, and upon recognizing setting of the FAX 1 at a destination of storing image data up to a specified time, the control section 23 transfers image data added with destination data and transmission time data immediately to the FAX 1 (S210-S290). When a reception completion signal is not received from the FAX 1 (N: S300, retransfer of image data is executed (S290).