In an Internet facsimile apparatus, a facsimile controller temporarily stores data received from a G3 (Group 3) facsimile apparatus or the other terminal unit to communicate with. A packetizer/depacketizer packetizes the data sequentially read out in accordance with size information fed from a size information storage and feeds the resulting packets to a UDPTL controller and a buffer. The packetizer/depacketizer determines whether data received from the other terminal unit and decoded is a response to data sent from the G3 facsimile apparatus or retransmitted data, and delivers a response detection signal representative of the result of decision to the UDPTL controller. In the UDPTL controller, a filtering circuit deletes stored past data in accordance with the response detection signal representative of a response. The apparatus reduces a load on an IP (Internet Protocol) network.