Provided is a sound output device worn on an ear of a listener and used, and having listening characteristics of an ambient sound in a wearing state. A sound output device 100 includes a sound generating portion 110 that generates a sound, a sound guiding portion 120 that takes in the sound generated in the sound generating portion 110 from one end 121, and a holding portion 130 that holds the sound guiding portion 120 in the vicinity of the other end 122. The holding portion 130 is engaged with an intertragic notch, and supports the sound guiding portion 120 such that a sound output hole of the other end 122 of the sound guiding portion 120 to face a depth side of an ear canal. Even in a state where the listener wears the sound output device 100, the sound output device 100 does not block an ear cavity of the listener, and the listener can listen to the ambient sound.