PURPOSE: To increase the number of times of retransmission limiting by retransmitting a data based on the number of times of a comparatively large retransmission limiting to a first communication and retransmitting the data based on the number of times of the prescribed retransmission limiting while the communication speed slows down succeedingly.

CONSTITUTION: A CRC error detection code added at energy byte of a digital signal outputted from a MODEM 14 is checked by an error detection section 15 to check whether or not a transmission error takes place, A digital signal from the MODEM 14 is decoded or the digital signal sent from this die is coded and fed to the MODEM 14 in a coder/decoder 16. A scanner controller 17 controls an image scanner 18 reading an original to apply picture data input. A printer controller 19 controls a dot printer 20 applying print-out of the picture. A sub RAM 21 stores tentatively a picture data from the controller 17. A memory set with the number of times of retransmission limiting a, b, c, d is provided on a main RAM 13 corresponding to address A, A+1, A+2, A+3.