IMAGE FORMING DEVICE

PROBLEM TO BE SOLVED: To provide an image forming device that can enhance the entire efficiency by printing out image data received from an external processing unit with less data amount with priority when the amount of the image data received from the external processing unit is less while receiving a huge amount of FAX reception data. SOLUTION: In the case of receiving a print command from the external processing unit while receiving FAX data, when a comparison means discriminates that a data quantity of the image data received from the external processing unit is less than a reference quantity, a control means interrupts the printing of the FAX data received by a FAX communication means and prints out the image data received from the external processing unit with priority.