PURPOSE: To prevent the offending ringing of a telephone set due to a ringing signal by ignoring the ringing signal when the ringing signal is transmitted from another line during communication, and disconnecting the line from a data communication part and the telephone set.

CONSTITUTION: The data communication equipment is provided with a main control part 1, read part 2 to read pictures, recording part 3 to record pictures, facsimile communication part 4 for normal communication, telephone set 6, off-hook detection circuit 7 to detect the off-hook, and ringing signal detection circuit 8 to detect the ringing signal from a line 5 or the like. In this case, when there is an incoming call in the other line during the communication at the data communication part 4, this is ignored, the line is not caught and also, it is disconnected from the telephone set 6. Thus, the offending ringing of the telephone set 6 can be effectively prevented, and the line can be prevented from being used by useless line catching.