It is an object of this invention to provide a data communication apparatus which can prevent erroneous transmission of data to unrelated persons. When a plurality of addresses are set upon operation of an operation unit, information indicating that a plurality of addresses are set is displayed on a display unit to notify the operator of the information. No data is transmitted until the operator performs confirming operation to approve transmission of data to the plurality of addresses. When the operator performs confirming operation, a multi-address call is executed.