To provide the infrared ray transmitter with an excellent transmission characteristic.

The infrared ray transmitter 10 is used in combination with a transmitter 2 that sends a sum signal SMIX between a signal SFM modulated by a video signal and signals LFM, RFM modulated by audio signals in terms of an infrared ray 3. The transmitter 10 is provided with an infrared ray photosensor 11 that receives the infrared ray 3 and provides an output of the sum signal SMIX, a circuit 12 with a filter characteristic to extract the signals LFM, RFM modulated by the audio signal from an output signal of the infrared ray photosensor 11 and an infrared ray emitting element 14 emitting an infrared ray 19 whose luminous intensity is controlled by the signals LFM, RFM modulated by the audio signal extracted from the circuit 12 with this filter characteristic.