According to one embodiment, a transmitter including an AV transmission unit including a first transmission unit which transmits video/audio data according to a method 1, and a second transmission unit which transmits video/audio data according to a method 2, with a clock signal inserted in a data signal, and a communication unit which performs the information communication with the receiver by a predetermined standard signal, a communication channel switch unit which transfers a video clock signal to a clock terminal of an HDMI if the video/audio data is transmitted by the first transmission unit, or transfers a first predetermined standard signal output from the communication unit if the video/audio data is transmitted by the second transmission unit, while the communication channel switch unit transfers a second predetermined standard signal received by an HPD/RSV terminal of the HDMI even in transmission by any of the first and second transmission units.