To obtain the headphone in which a change in sound quality is suppressed even when an output impedance of an audio equipment differs by connecting a resistor in series between an acoustic unit and a headphone plug and connecting a resistor in parallel with the acoustic unit.

A resistor R1L(R) is inserted to a headphone cord 4L(R) interconnecting a left (light) ear acoustic unit 1L(R) and a headphone plug 5 and a resistor R2L(R) is connected in parallel with the acoustic unit 1L(R). With respect to the nominal impedance ZL of the acoustic unit 1L(R), the resistance of the R1L(R) is selected to be nearly equal to 10Ω-ZL and the resistance of the R2L(R) is selected as R2L(R) approximately, ≥ZL and ≤2ZL so that the drive impedance when viewing from the acoustic unit 1L(R) is not susceptible to the effect of the output impedance of the audio equipment. Thus, even when the output impedance of the audio equipment differs, the open type headphone can suppress a change in the sound quality.