The present invention relates to a facsimile apparatus for providing a single/dual side mixture mode capable of transmitting and receiving original images including single/dual side mixture efficiently. Under control of a CPU 22, information indicating presence/absence of back side image information corresponding to transmission/reception image information is informed together with page number and image front/back information, by a post message signal transmitted from a transmitter to a receiver. If the image information read from a back side of an original is substantially entire-white, the transmitter omits transmission of back side image information having the entire-white. In this case, by informing information indicating absence of back side image information corresponding to front side image information from the transmitter to the receiver by the post message signal, single/dual side mixture image informations can be transmitted and received.