To prevent a T5 timer from operating unnecessarily during color image communication as to G3 color facsimile using a nonstandard function.

A control means 55 places a color communication means 51 or monochromatic communication means 52 selectively in operation. For a color image communication, a signal S1 indicating whether or not a color communication function is available is sent from a reception side and a decision means 53 makes a decision. When it is decided that there is no color function on the reception side, the timer time of the T5 timer 54 is set to one minute of the G3 standards. The control means 55 decides communication abnormality when the timer time is elapsed during a communication and disconnects the line. When the color communication function is available on the reception side, a signal S2 indicating a timer time in an HLDC information field is sent from the reception side together with the signal S1, so the decision means 55 sets the timer time (120 seconds) in the timer 54. The color image communication becomes long in the print time of one page, but the T5 timer is set longer than at monochromatic communication time, so the line is not disconnected unnecessarily.