PURPOSE: To eliminate the operating inconvenience in a facsimile communication system by copying a facsimile data file requested for transmission to a file produced in an external memory device and transmitting the copied file to a facsimile equipment which is designated by an application program.

CONSTITUTION: The external memory device 2 is connected to a host computer 1 and simultaneously a facsimile equipment 4 is connected to the computer 1 via a communication network 3. The computer 1 is provided with a facsimile control program 5 and an application program 6. The program 5 includes a request reception means 7, a copy means 8, and a transmission means 9. Then a facsimile data file 10 requested by the program 6 of the computer 1 for transmission is copied to a file 11 and sent to the equipment 4. Thus it is possible to eliminate such operating inconvenience where access is impossible to the facsimile data file requested for transmission until the end of the transmission of the data file is finished.