PURPOSE: To instantly perform a notification of communication charge by recording the communication charge in a disconnection instruction packet to be transmitted from a packet exchange to a terminal at the time of the termination of the communication, in a packet communication.

CONSTITUTION: When a packet exchange 21 to be connected to an ISDN receives a call control packet from Q a terminal 20, a call control part 22 performs the setting of the call. When it becomes a communication state, a data transfer part 23 controls the transfer of a data packet. A charging data counting part 24 counts the user data of the packet to be a charging object. At the time of the termination of the call, a communication charge calculation part 25 calculates the communication charge by this data and the address of a communication party. A packet edition part 26 edits a disconnection instruction packet including communication charge and transmits it from an exchange 21 to a terminal 20 by the control of the call control part 22.